A white barn stood at a short distance from the house. A barn of that size, Rick thought, meant a pretty substantial farm. He searched for signs of life and saw none. There was a boat, he noticed, an outboard skiff perhaps fifteen feet long, pulled up on the bank under an oak tree at the edge where the lawn met uncut field. A lawn table and chairs under the big willow looked inviting, and he speculated that Merlin and friends must spend considerable time there. Some of the chairs were of the padded variety, covered with plastic wet from the morning dew.

Scotty pointed to the roof of the mansion. "Must be a ham radio operator there. Look at that hay rake."

Both Rick and Steve had the same thoughts as they stared at the tall antenna, with its cluster of small rods joining a single main bar at right angles on top of the pole. The antenna might be needed for fringe-area television—or, on the other hand, it might be a communications antenna, as Scotty had said.

"Looks interesting," Steve said.

The creek flowed only a little distance past the mansion before it became so narrow that Orvil Harris had to turn for the trip downstream. As the crab boat came abreast of the mansion again, Rick looked to the other side of the creek and saw the duck blind. It wasn't exactly opposite the house, being designed so that gunners in the blind would shoot diagonally across the creek and downstream, rather than near the house itself.

The blind was on stilts, made of board, with a big "picture window" without glass through which duck hunters could fire freely. It was designed for entry by boat, and there was a line of poles sticking up from the water that marked the boat's docking place. In season, the entire blind including the poles would be covered with a screen of fresh foliage, so that hunters, blind, and boat would seem like a natural object to any duck that flew by.

Rick saw that the entrance, at the point where the boat would nose in, was downstream from the mansion, at the back corner of the blind. Anyone approaching from the swamp behind the blind could enter unseen from Calvert's Favor.

Not until they were back at the cove did any of them speak.

"That antenna was odd," Steve said. "Did you ever see anything like it, Rick?"

"Not exactly," Rick admitted. "It could be for TV, although it's an unusual design, or it could be some kind of ham rig, as Scotty said."

"Or it could be something else," Steve concluded.

"No sign of a flyin'-saucer launcher," Orvil Harris said. He was stoking his battered brier.

Rick grinned. "I wouldn't know one if I saw it."

"Well, that wraps it up," Steve said. "Let's get aboard the runabout and head home. I've got to make a plane." He shook hands with Orvil Harris. "Glad to have met you after waving at you for so long."

"Likewise. Now, you let me in on this if you can. I'm Link's only kin hereabouts, so I feel responsible, so to speak. Call me up. I'm in the phone book. I'll keep crabbin' in this creek until further notice, so you can find me here until midmornin' any day."

"We'll let you know if anything comes up," Rick agreed.

Scotty borrowed a boat hook and pulled the runabout closer, then he stepped to the forward deck while Steve and Rick got into the seat. Scotty pulled up the grapnel while Steve started the motor. In a moment they were waving to Harris as the runabout headed for home.

It was full daylight now, and the rim of the sun was just above the trees on the horizon.

"Two items from the morning's work," Scotty summed up. "We know how the mansion can be watched, and we have an odd kind of antenna. Anything else?"

"We have an ally," Rick reminded. "Orvil Harris."

"We bought him on pure faith," Steve pointed out. "It isn't often I stake the game on a man's face, but if Orvil Harris isn't a sound individual, I'll lose my faith in human nature."

Back at the farmhouse, Steve made fresh coffee and toast. While the boys relaxed sleepily, he went to a closet and brought out a case and a leather gadget bag.

The boys sat up and watched while he opened the case. Rick gasped. It was a telescope, a marvelously compact reflector type, precision made and very expensive. Rick had often studied the ads of this particular model, and he looked at it with some envy. He could hardly keep from picking it up.

Steve opened the gadget bag and brought out a Polaroid camera and set of rings. Then he returned to the closet and brought back a sturdy tripod with a geared head.

"Here's the equipment," he said. He took the telescope from its padded case, and screwed its base to the tripod, then he adjusted the tripod until it was standing securely.

"Watch this," he commanded. "You'll have to do it, because you can't carry the whole thing assembled."

Using the rings, which were adapters, he fitted the camera to the eyepiece of the telescope. "That's all there is to it. You focus the 'scope eyepiece by turning this knurled knob. Then you set the camera to infinity, adjust the iris for the proper light, and put the camera in place. Any questions?"

"What aperture?" Rick asked. "Normal exposure?"

"Make it one f-stop less than you'd use if you were taking the picture through a regular camera with a long lens. Anything else?"

Scotty grinned. "It's pointless to ask what you want us to do with this. We're to get pictures of that antenna—from the duck blind."

"Plus anything else that looks interesting, including the occupants," Rick added.

Steve spread his hands in an expressive gesture. "What more could an instructor want than students who know the answers before the questions are asked? I won't even tell you to be careful, because I know you will."

"We will," Rick assured him.

"All right. Listen, boys, we have no idea what we're up against, but we do have some facts." Steve ticked them off on his fingers. "One, flying objects originate at the mansion. There's no other place on the creek that seems likely. Two, the house is inhabited by a man who doesn't like questions. Three, said man has a bodyguard who gets rough. Four, one man already is missing, perhaps because he got curious. Enough said?"

The boys nodded soberly.

"Then go to it, whenever you feel like it—after you've dropped me at the airport, that is. Be here by four this afternoon. If I don't call, meet the five-o'clock flight. If I do, it will mean I've gotten tied up."

Steve hesitated. "Just one more thing. Be really careful. All I have is a hunch, but that hunch tells me we're up against something dangerous. If Link Harris is dead, as he probably is, there's a fair chance he was murdered."

The agent's keen eyes met theirs in turn. "Don't get into a spot you can't get out of," he concluded.



CHAPTER IX

The Duck Blind

Orvil Harris had described the opening to the hidden waterway, but when the boys examined the line of reeds and marsh grass there was no sign of it. "He said thirty yards downstream," Scotty remembered.

Rick was at the wheel of the runabout. "Climb out on the bow," he suggested. "Take the boat hook with you. I'll just keep nosing in until we find it."

"Okay." Scotty took the short, aluminum boat hook from its fastenings in the small cockpit, stood up on the seat, and stepped over the windshield to the bow. For a moment he surveyed the shoreline from his higher vantage point. "There's a place that looks promising." He held the boat hook out like a spear, pointing.

Rick put the runabout in gear, and moved forward at idling speed. Looking over the side, he could see the bottom clearly. They were in only two feet of water, and the outboard was stirring up mud at the stern.

"No good," Scotty called. "That one doesn't go anywhere. Try upstream another six feet."

Rick turned the boat, watching for the opening Scotty had spotted. He saw it a moment later. "Looks too small," he called back.

"I think it opens up. Go ahead slow."

The runabout nosed up to the almost solid line of tall swamp grass, and Scotty leaned forward. "I think this is it. Take it easy."

The heavy grass rubbed on both sides of the boat, but nothing impeded its progress. The runabout pushed through the brown-green swale until it was almost enclosed by the grass. Then they were through, into a narrow channel with high grass on both sides. It was hard for Rick to see ahead because of the turns, and Scotty served as his eyes, motioning from one side to the other as the channel shifted.

Rick wondered if the sound of the outboard motor could be heard at the mansion, and decided it probably could not. The heavy marsh grass was a good sound baffle and the motor was relatively quiet. He leaned out, trying to see ahead. There were many birds in the swamp, and next to the boat a surprised snapping turtle looked up briefly, then scurried into the mud for cover.

The channel was narrowing now. Scotty looked back and drew his hand across his throat in the old signal to "cut." Rick instantly killed the motor.

"I'll pole us," Scotty said softly. He began using the boat hook as a pole, digging it into the bank and pulling the runabout ahead. Finally he stopped, and wiped sweat from his face. "This is about as far as we can go."

Rick took a swipe at a black fly that bit him on the arm. "Okay. Let's collect the gear and get started."

Scotty tied the boat to a projecting root while Rick took the equipment from its place under the seat and put it within reach on the forward deck, then jumped ashore. His feet hit apparently solid ground, but kept right on going down into a foot of ooze.

He lifted one foot that was a black blob of mud, tried to locate more solid footing on which to place it, and gave it up as a bad job. He leaned over and took the telescope case and tripod.

Scotty picked up the Polaroid camera and their binoculars and came ashore, sinking into the swamp as Rick had done. He grinned wryly. "We're up to our knees in this mystery already."

Rick lifted a foot with five pounds of mud clinging to it. "If we get in it up to our hips, we'll have a fine time getting out. How far do you think it is to the duck blind?"

"Maybe twenty-five yards. Not much more than that, maybe less. Come on."

Slowly, because of the need to haul each foot out of the mud, the boys started through the swale. The marsh grass was over their heads, forming a thick screen. The grass, however, was no handicap to the biting flies. Within a few seconds each boy was carrying equipment in one hand, using the other to fight off the swarms. An occasional mosquito added to their discomfort.

The muddy ooze thinned, then gave way to higher ground. The marsh grass was less thick and there was an occasional clump of willow. Rick studied the terrain ahead, and in a moment caught sight of dark-green foliage among the brown tips of swamp grass. In a few more feet he made out the tops of trees, and then the glint of sunlight on the aluminum of the antenna they had come to photograph.

Scotty had seen it, too. He stopped and the boys consulted.

"We're about twenty yards too far upstream," Scotty guessed.

Rick estimated as best he could. "I think you're right. Let's stay on high ground and head downstream a little. We must be almost there."

Scotty turned and Rick followed, waving uselessly at the cloud of insects. He was grateful for the advice Steve had given them to wear long trousers and long-sleeved shirts. If they had been wearing shorts, the insects would have had free access to several square feet of bare hide.

Both boys counted steps automatically, and after twenty paces downstream, Scotty turned toward the mansion once more. They pushed through the tall grass into thick mud, then into water with a deep muddy bottom. A few more steps and the grass thinned. Scotty stopped and motioned Rick back. They moved sideways, then forward again, and emerged with the duck blind between them and Calvert's Favor.

Rick thought to himself that it had been pretty good navigation, considering that most of the journey had been blind, in grass over their heads. Apparently Scotty thought so, too. He turned and gave Rick a big grin, then headed for the rear of the duck blind.

The water deepened, washing off some of the mud. Rick reached down and splashed a handful on his face. It was warm. He saw a wet black head emerge from under the duck blind and speed for shore. It was a startled water rat. Alerted by the small splash of their coming, the rodent decided to take better cover. Then they were at the corner of the blind where the entrance was located.

The floor of the blind was level with their chests. Rick looked in. There wasn't much space, since the blind had been built to provide only a place for hunters to sit, wait, and then shoot from kneeling or sitting positions.

Both boys put their equipment on the dry wooden floor. Then Rick swung himself up and pushed the equipment back to make room for Scotty. For a moment they sat on the floor, resting. Coming through the swamp had been exhausting work.

After a few moments' rest, Rick moved to the side of the duck blind and found a small opening, a square window about six inches on a side, that had apparently been made to give the hunters a view in that direction. The opening was near the forward, upstream corner, and it looked out on Calvert's Favor.

Merlin the mysterious and his two close companions were sitting under the willow tree enjoying something liquid from tall glasses. As Rick watched, a fourth man, evidently a servant, brought a tray on which a silver pitcher rested. The boy could see the trickles of water cascading down the outside, and knew they were caused by moisture condensing on the cold metal of the pitcher. He moistened his lips. A fine pair of dunderheads, he and Scotty were. They had come without even a canteen of water.

"Easy shot," he whispered to Scotty. "Let's set up and take the pictures, then get out of here. I'm getting thirsty just watching them."

Scotty adjusted the tripod, while Rick took the telescope out of its case with reverent hands. It was a beautiful and delicate piece of equipment, Steve's personal property, and he appreciated the trust the agent had placed in them by allowing its use. He fitted the instrument to the mounting screw on the tripod, then aimed it through the six-inch window. When he squinted through the eyepiece, he saw only willow branches, but, by keeping his eye in place and cranking the geared tripod head, he quickly aligned the telescope with the trio under the willow.



The telescope had a fixed focus, and was designed for looking at stars. Consequently, the field of vision was extremely narrow at the short distance across the water, and Rick could only manage to get Merlin and his small, insignificant-looking companion into the frame. What's more, they were upside down, as is common in reflecting telescopes. The boy knew there was an erecting prism in the case, a device that would put the image upright, but it couldn't be used with the camera. Anyway, it wouldn't matter, since the print could be turned over.

He studied the faces in the upside-down position. The telescope gave him an even better close-up than at the restaurant. Again he groped for the identity of the white-haired man, but it eluded him.

Scotty tapped him on the shoulder and motioned that the camera was ready. Rick moved aside and his pal quickly fitted the camera to the telescope and tightened the mounting rings. Rick nodded to indicate that the telescope was on target, and Scotty tripped the camera.

The advantage of the Polaroid camera is that the picture can be seen within seconds. Scotty quickly went through the simple routine, and within a quarter of a minute the boys were looking at the photo. It was an excellent close-up, but a trifle dark. Scotty opened the iris on the camera another stop and Rick rechecked the alignment. Scotty snapped the picture and processed it. This time it was perfect, only slightly hazy because of the rising heat waves across the hundred yards of distance.

Rick readjusted the telescope for a full view of the third man. His picture was added to the others. Scotty wiped both with fixative and put them on the floor to dry.

The antenna was next. Rick focused on it without difficulty, but the field of view was so narrow that he couldn't see all of it. They would have to photograph it in two sections, then fit the prints together.

Five minutes after their arrival at the duck blind, they were back in the swamp, the pictures protected in a plastic bread wrapper Rick had brought. They cut directly across the swamp and emerged, hot, sticky, and dirty, only a few yards from the boat. They stowed the equipment wordlessly, then poled backwards into the wider channel. It was too narrow to turn, so Rick started the motor and backed out with great caution.

Once in the clear, they headed at top speed for Steve's, tied up at the pier, and plunged into the water without even bothering to remove their clothes. Their only precaution was to empty their pockets.

Rick luxuriated in the coolness of clean water, then stripped to his undershorts and threw his sodden clothes onto the pier. Only when he was sure he had washed off the last of the clinging mud did he pull himself up to the houseboat cockpit, Scotty following.

They toweled and put on clean clothes, then carried the equipment back to the farmhouse. Two bottles of Coke apiece from the refrigerator had them feeling normal again. Over the last one, they studied the photos.

"I don't think we've ever known Merlin," Rick said thoughtfully. "We've seen him, but we don't know him."

Scotty scratched a mosquito bite. "Think he might be some kind of public figure?"

Rick looked up sharply. "I think you hit it! If that's true, we should be able to get him identified easily."

"Steve could do it through JANIG," Scotty suggested.

"It would take too long. He won't be home until tonight, and the picture wouldn't reach JANIG until tomorrow. Then it would take a day to check it out."

"Are we in a hurry?" Scotty asked.

Rick chuckled. "I am. But don't ask me why. Look, I'll bet Duke or Jerry could identify it by going through the newspaper morgue." Their newspaper friends were owner-editor and reporter for the Whiteside paper back home.

"They're on vacation," Scotty reminded him. Once each year, the paper was turned over to a friend of Duke's, a former newspaperman turned professor of journalism, who used the occasion to give some of his students practical experience.

That was true, Rick remembered. Neither Duke nor Jerry would be available. Who else did they know who could help? Suddenly he snapped his fingers. "I've got it! Ken Holt would help, if we could get the picture to him."

Ken Holt, the young newsman whose adventures were favorite reading for Rick and Scotty, had once asked Spindrift for help, and Rick had given him a set of pocket-size radio transceivers of the kind known as "The Megabuck Network."

"Sandy Allen is a photographer," Scotty pointed out. "He might know these people."

Rick took a chair next to the telephone and dialed the operator. "A person-to-person call," he stated, "to Mr. Ken Holt, at the Brentwood Advance, Brentwood, New Jersey." He put his hand over the mouthpiece. "Let's hope he and Sandy aren't off on an assignment somewhere."

Luck was on their side. Ken Holt was in, and he was delighted to be of help. "Put the picture in the mail," the young reporter suggested. "If you make it airmail, special delivery, we'll have it first thing in the morning. With luck, we might even get it tonight. We'll phone you as soon as we have an identification. Incidentally, the Megabuck units worked like a charm, as I told you when I wrote. Thanks a lot."

"Glad they were helpful," Rick replied. "We'll hurry to town and get the picture in the mail right away."

He hung up and nodded at Scotty. "We'll get the picture ready, and take it to town when we go to pick Steve up. If we're a little early, the letter probably will go out on the early evening plane to Washington."

Scotty nodded. "What time is it?"

Rick glanced at his watch. "Nearly three. We'll be ready to take off as soon as Steve calls, or doesn't."

"If he calls, that means he won't be back," Scotty reminded.

"No matter. We'll go to town anyway, and have an early dinner."

Rick had envelopes and letter paper on the houseboat. He wrote a brief note to Ken, addressed the envelope, and printed AIRMAIL SPECIAL DELIVERY on both sides, then enclosed the best picture of Merlin and sealed it. Scotty spent the time on a small repair job, taping up the neoprene gasoline hoses that carried fuel to the houseboat motors. By the time he was finished, it was nearly four. The boys went into the house to wait.

Steve called on the dot of four. "Rick? ... Steve. I'm sorry, fellow. I have a little more to do on this case, and I'll have to stay over. Everything going all right?"

Rick briefed him quickly on the day's events and Steve replied, "It takes about half an hour for a letter to make the early evening plane. Allow enough time."

"We will," Rick assured him. "Anything new on the sighting data?"

"Not yet. I sent the cards to the computing center, but they won't have time to run the data through until tomorrow or the next day. Make yourselves at home, and don't spend all your time on flying stingarees. Get in some fishing and swimming."

Rick assured him that they were enjoying the vacation and would try to get in some fishing. He hung up and turned to Scotty.

"He'll be in tomorrow on the same plane. He wants us to get in some fishing."

Scotty chuckled. "I thought he knew you better than that. Give you a mystery to chew on and there's no room for anything else in that thick Brantish skull."

"We'll solve this one," Rick said confidently. "Then we'll fish."

Scotty just grinned.



CHAPTER X

Ken Holt Comes Through

Somewhere in the oak trees across the creek a cardinal sang his lovely evening song. An osprey, etched in black against the dark blue of the sky, whirled in lazy circles watching the water below. A muskrat appeared briefly, his sleek head making a V of ripples in the calm water.

Rick and Scotty, sprawled comfortably in beach chairs on the lawn in front of Steve's house, sipped the last of their iced tea, and watched the movements and listened to the sounds in companionable silence. Both boys, admitting that, for the immediate present, they were slightly overdosed with rich food, had agreed to settle for a sandwich and iced tea. A brief stop at a store en route back from the post office had provided the necessities.

Rick was physically relaxed, but mentally active. It was characteristic of him that he never let go of a puzzle until he had found a solution, or had tried all possibilities and been forced to admit defeat. He was a long way from defeat at the moment. The case of the flying stingaree was just getting interesting.

"What are the flying stingarees?" he asked quietly.

Scotty shifted position in his chair and looked at Rick quizzically. "You don't expect an answer. But I can tell you a few things they are not."

"Tell away," Rick urged.

"They are not flying saucers, aircraft, kites, sting rays, birds, fish, or good red herrings. Beyond that, deponent sayeth not, as the legal boys say."

"Uh-huh. And why are they not flying saucers?"

"For the same reason they're not aircraft. If you recall all the talks with people who've seen them, they don't maneuver, and they don't travel very fast. They appear—or they're noticed, let's say—and they just get smaller and smaller until they vanish. They move, but not much."

Rick nodded. "The circle we drew around all the sightings doesn't cover a very large territory. All the sightings have been within that circle. People had to look toward Swamp Creek to see the objects. Yet, they did something interesting. They grew smaller. What makes things seem to grow smaller?"

"Apparent size decreases with distance," Scotty replied promptly.

"Sure. And how do you get distance, when the sightings are all within a circle only a few miles in diameter?"

"Only one way. With altitude. The things had to be going up."

Rick agreed. "That's how I figure it, too. It also explains why the circle of sightings is so small. Above a certain altitude, the objects are no longer visible. Or they're not so visible that they attract attention. I suppose we could work out some calculations. How large an object can be seen readily at what distance? Then we could apply a little trigonometry and figure their size."

"We could," Scotty agreed, "but do we need to? Let's assume the object you saw was typical. How big was it?"

Rick thought it over. He had had only a quick glimpse, and the background had been the gray of the storm. His vision had been obscured because of the rain. "Maximum of ten feet across and maybe eight tall. It was probably less."

"Okay. So the reason sightings are confined to this area is because the objects are fairly small. When people see them, they're relatively close, and fairly low. Even the small planes that fly from the airfield are much bigger than the flying stingarees, but when the planes go over at about five thousand feet, they seem tiny. At that altitude the flying stingarees must be at the limit of really good visibility."

"I read you loud and clear. So the objects are sent from Calvert's Favor, and they climb. They don't climb straight up, though. The wind carries them. The reason I think so is that the one I saw must have been driven by the wind, right down the creek toward me. It didn't climb until it got away from the funneling effect of the creek and into the river, then it went up pretty fast. At least it seemed to have risen fast when I looked over the top of the boat at it."

Scotty crunched an ice cube. "We're getting somewhere. There's only one kind of unpowered, vertical rising thing I know of. Are you with me?"

Rick finished his drink. "Balloon," he said crisply.

"On the beam," Scotty approved. "The only thing that doesn't fit is the shape."

Rick asked, "What's a balloon? It's just a gas-tight container. We're used to thinking of balloons as spheres, because it's the most efficient shape for internal pressure. But a balloon can be any shape. Another thing—balloons for high altitudes aren't fully inflated on the ground. Maybe the flying stingarees have a different shape when they get higher and in less dense atmosphere where the gas distends them."

"An odd shape could be used as camouflage, too, if you didn't want people to recognize the balloon. But why would a strange assortment of characters like Merlin and company send up balloons?" Scotty wondered.

Rick smiled. "I've been wondering that myself. Would they send up a balloon that didn't carry something?"

"I don't know. Was the one you saw carrying anything?"

Rick sat upright. "Maybe it was! You know, I haven't even thought of it since then, but I think there was a splash when it went by. Something sort of clanged off the rail over me, even if it didn't dent the rail. Do you suppose the thing dropped its payload right next to us?"

"You'll have to decide that," Scotty said. "If you heard something bounce off the rail, then a splash, I'd say there might be a pretty good chance that's what happened. I couldn't see any marks on the rail when we looked." They had checked the rail during the first day at Steve's.

Rick closed his eyes and made himself remember what it had been like when he went down the catwalk to the bow. His mind drew a picture, and he saw himself bent forward into the wind. In his memory he felt the slashing rain, the slipperiness of the wet anchor line. He could visualize the water whipped into dimpled wavelets by wind and rain. He saw the flying stingaree loom, and saw himself dropping flat. There had been a clang as something hard hit the rail! There had been a splash!

He went over it again, searching his memory for details he had forgotten or which had only registered vaguely at the time. He studied the shape and texture of the object he had seen so briefly. He saw its red eyes open and glare at him, saw the extended claws reaching....

He came out of his chair with a yell, arms extended to defend himself.

Scotty stood next to him in the darkness. "Hey, take it easy, Rick! I didn't think I'd startle you so when I shook you."

Rick stared. "Did I fall asleep? I must have. I was trying to remember, and suddenly I was dreaming about red eyes and claws—"

Scotty laughed softly. "If you've got to have nightmares, at least do it in comfort. Let's go to the boat and go to bed."

Rick dreamed no more of the flying stingarees. In the morning he couldn't have said what his dreams had been about, except that they had been pleasant.

In the bright glare of morning, the whole thing seemed dreamlike. It was preposterous to imagine that flying objects, probably balloons shaped like stingarees, were launched from a famous mansion that dated back to the days of the early Maryland colony. But the sighting data couldn't be ignored. Dreamlike or not, something strange was going on at Calvert's Favor.

The boys breakfasted in the farmhouse, reducing Steve's supply of eggs substantially and wiping out the bacon reserve. "We'll have to shop sometime today," Rick observed. "Steve has plenty of food here, but we don't want to use it when there's a store so close."

"Sure," Scotty agreed. "But when? It may have to wait until we go after Steve. We can't very well leave the house, or at least both of us can't. Ken Holt might call."

Rick nodded and poured himself a cup of coffee. He had thought of that. They had to give Ken time to get the picture and check it out. By the latest, they should hear before noon—unless the job turned out to be very difficult. That would leave four hours before they would have to leave the house to pick up Steve. Four hours was time enough for the investigation Rick had in mind.

After breakfast they settled down with the data sheets and notebook to review them once more. But only one additional fact emerged. Two people thought, but weren't absolutely sure, that they had seen a spurt of fire from the flying stingarees. Rick wondered if they had seen a sudden flare of sunlight from some highly reflective part of the object.

It was two minutes before nine when the phone rang. Both boys jumped, but Rick got there first. "Hello?"

"Rick? ... This is Ken. Why don't you give us something hard to do? The envelope arrived three minutes ago, and I was just taking the picture out when Sandy walked in. He took one look and asked what I was doing with a snapshot of Lefty Camillion. The hair is white and the mustache is gone, but it's Lefty."

Rick gasped. "My sainted aunt! Of course! I should have known it myself."

"There's more. Sandy recognized Lefty's small friend too. This is an odd one, Rick. The man is Dr. Elbert K. Drews. He was fired six months ago by Space Electronics Industries. It was a big story for us, because the plant is located in the next town. The reason he was fired came out during the monopoly investigations. Turned out he had been selling the firm's industrial secrets to its competitors. It was a shock, because he had such a big reputation as an electronics wizard. He got some kind of national prize a year ago for developing a new high-speed system for something. Let's see—here's my note. It says, 'Dr. Drews was the originator of a new and unusual system for the rapid telemetry of data from space. The system is considered remarkable for its compactness and speed of operation. The ground installation is scarcely larger than a console-model television set.' Hope that means something to you, Rick."

"Thanks a million, Ken. It seems to fit, but I'm not sure how."

"Let us know if you find out. And if we can do anything else, you know the phone number."

"We'll call if anything comes up. Thanks again, Ken."

Rick hung up and stared at the phone thoughtfully, trying to fit this new information into the scheme of things. Scotty had been sitting on the edge of his chair since the conversation started. He said, with some exasperation, "Well? Out with it!"

"Mr. Merlin is Lefty Camillion. His pal is an electronics wizard who was fired by Space Electronics Industries for selling industrial secrets to the firm's competitors." Rick rapidly sketched in the rest of the conversation.

Scotty sank back into his chair. "His hair was black, and now it's white. He must have been keeping it dyed, and decided to go natural. And he shaved off that mustache. Probably that was dyed black, too."

"You're right." Rick shook his head in dismay. Lefty Camillion, whose first name was Thomas, was a notorious crime syndicate leader who had come into prominence about two years ago during Senate investigations of racketeering. In three days Camillion had become a television personality, of sorts, when it became clear that he apparently was responsible for a number of murders and a thousand lesser crimes, although he himself had not done the actual killings. There was insufficient evidence to jail him, but enough to deport him. He dropped out of sight while his lawyers were fighting the deportation proceedings. Now he had shown up again, on the Eastern Shore.

"A crime syndicate chief, a crooked scientist, flying stingarees, an old mansion, a peculiar antenna, and a missing crabber. What does it add up to?" Rick demanded.

Scotty shrugged. He didn't answer. There was no answer—yet.



CHAPTER XI

On the Bottom

There were three wooden cases stored in the full-length closet in the houseboat cabin. Rick and Scotty took the two bulkiest to the cockpit and opened them to disclose full skin-diving equipment. The boys had made the cases themselves, to be carried like suitcases. Each held a single air tank, regulator, mask, fins, snorkel, underwater watch, depth gauge, weight belt, equipment belt, and knife. The third case contained spears and spear guns, but they wouldn't need those in searching for the object that had splashed near the houseboat.

While Rick checked the equipment, made sure there was sufficient air in the tanks, and put on the regulators, Scotty searched for a heavy stake and something with which to drive it. He found a sledge hammer in Steve's workshop. At the edge of the woods was a pile of saplings that had been cut to make a fence. He chose a sapling that would serve as a stake and took it back to the boat.

One of the spare lines that the houseboat carried was quarter-inch nylon. Scotty fastened one end of the small rope to the sapling, about halfway up, and secured it with a timber hitch. Then he wound the rope on the sapling as smoothly as possible.

Rick finished checking the equipment and announced that he was ready.

"Same here," Scotty replied. "Let's get into swim trunks."

As the two changed, Rick asked, "Suppose we find something, but can't get it up without help? How do we mark the place?"

Scotty paused. Normally they would simply attach a line to a float and secure the float to the object. But a float would attract attention. "Take bearings?"

Rick shook his head. "The boat will be swinging at anchor. It might be hard to get good bearings. Would a piece of fish line work? We could tie it to the object, carry it to the shore, and secure it to something underwater. The line would sink. Later, we could just drag until we caught the line."

"It would work," Scotty agreed. "There's a new spool of heavy line on the shelf in the closet. Fifty yards. That should do."

"Especially since the most we would need is fifty feet," Rick agreed. "I'll stick it in a belt pocket, just in case."

Back on deck, Rick started the houseboat's outboard motors and listened critically. They were operating smoothly. Scotty walked up the pier and untied the bowline. At Rick's signal, he stepped aboard on the foredeck, bringing the line with him. Rick cast off the stern line, pushed the houseboat away from the pier, then put the motors in gear.

The trip to Swamp Creek was a familiar one now. Rick cut corners, knowing he had enough water under the keel, heading directly for the creek entrance. Scotty came back to the cockpit and joined him.

"Do you suppose Orvil Harris will be around?"

Rick shrugged. "It's pretty late for a crabber. He's probably gone by now."

"I wonder if he'll ever see any flying stingarees come out of the creek."

Rick shook his head. "Most of the sightings are in the late morning or late afternoon. Only a couple were around dawn."

While the houseboat moved across the Little Choptank, Scotty checked the tide tables. He reported that the tide was coming in. It was about one hour from high tide. Rick had been studying the chart. "No problem," he said. "Mean low water averages four feet in the cove, with seven feet in the middle. Think your stake will be long enough?"

Scotty had placed the sapling with its winding of rope on the cabin top. He estimated its length again. "Depends on how deep the mud is. If it's more than three feet, the top of the stake will be under water."

"Three feet is a lot of mud," Rick said. "It's likely a lot less than that."

He turned into the creek mouth, throttling back. It would be hard to anchor precisely where the houseboat had been anchored that first night, but he was sure they could find the spot within twenty feet. Scotty went up on the bow and got the anchor ready.

"Use about thirty feet of line," Rick called. He took the houseboat to the exact center of the cove, as closely as he could estimate, then put the motors in reverse to kill the speed. When it fell to zero, he yelled to Scotty. Scotty lowered the anchor and made it fast, then hurried back to join Rick, who backed off until he felt the anchor dig in.

It was silent in the cove with the motors off. "I'll start," Rick offered, and at Scotty's nod he picked up his Scuba and slipped into the harness. His weight belt was next, then his fins. Finally he slipped the mask strap over his head, and put the mouthpiece in place. He took a couple of breaths to make sure he was getting air, then walked to the edge of the cockpit and fell backward into the water, letting his tank take the shock of landing. He slipped the mask off, took the mouthpiece out, and spat into the mask to prevent fogging, then he rinsed it, put it on, and replaced the mouthpiece.

Scotty had taken the sapling from the cabin top. He handed it to Rick, who dove with it, thrusting the sharpened end into the mud far enough so that the sapling stayed in place.

Rick surfaced again and swam to the boat, which had drifted a few feet. Catching the leg of one motor, he pulled the boat back to where the sapling projected above the surface. He held the boat in position while Scotty took the sledge and drove the sapling down until its top was only a few inches above the water. Rick tested the pole. It was firm.

He removed the mouthpiece, treading water. "Looks okay. I'm going to start."

"Good luck," Scotty called.

Rick submerged and swam down, using the pole as a guide. The rope, attached to the pole, was perhaps two feet above the bottom. He freed the end of the rope, unwound a few feet, slipped the end through his belt, and secured it with a slip knot. Then, hands extended, he began the slow work of covering the cove bottom inch by inch, searching for the thing that had splashed.

The boy swam in an ever-widening circle, the rope unwinding from the sapling as he moved. The unwinding of the line, which he kept taut, ensured that he would cover new ground each time he rounded the pole, but without missing any. He couldn't see, because his hands stirred up mud as he traveled. Only his sense of touch told him what was on the bottom. He wasn't afraid of grabbing a crab or an eel. All underwater creatures with any mobility at all get out of the way as fast as possible. He knew the compression wave caused by his movement would warn all living creatures.

His groping hands identified various pieces of wood, all natural, and assorted other objects including an old tire. There were cans, some of them food tins that had been opened, and some beverage cans, recognizable because of their triangular openings. Once he found a section of fishing pole.

It was a long, tedious job. The world closed in on Rick and there was only the murk outside his mask and the rhythmic sound of his own breathing. Only his hands, constantly probing the mud, were in touch with reality. He lost all sense of time. Once, to see how much ground he had covered, he pulled himself to the pole by the line, estimating his distance. He was about fifteen feet from his starting point. He returned to the full extent of the line and started the round again, after looking at his watch. He had to hold it close to see the dial through the murk. He had been down only twenty minutes, although the time seemed much longer.

Ten minutes later his hand swept over something smooth. Instantly he turned in toward the pole, and swam back around the circle for perhaps ten feet. Then, covering the ground again by crawling along the bottom, he felt for the object. His fingers touched it. His first impression was of something cylindrical, but he made no attempt to pick it up. He needed to explore it thoroughly, first. His breathing was faster, and he knew his pulse had accelerated at the moment of discovery. If this continued, he would use air too fast. He willed himself to slow his breathing, and for a few seconds he stopped altogether.

In that instant, Rick heard a slap on the water, then another. He waited, holding his breath. There was a pause, then more gentle slaps. He counted them.

One, two, three, four—the signal for danger!

He and Scotty had long ago agreed that four sounds underwater would be the danger signal. He reacted instantly. The fishing line was in a pocket on his equipment belt. He took it out and pulled line from the spool. Then, probing deeply with one hand, he pushed the line under the smooth object, reached across and down with the other hand. When his hands met, he passed the line from one to the other and pulled the line through. Now it was around the object. He tied the line quickly, then rolled over on his back and looked upward at the surface. He could gauge the position of the sun, even though he could see no details. Using the rays filtering through the murk as a guide, he oriented himself.

"Which bank?" He thought quickly. Danger could only come from the mansion, and that was on the south bank. He turned and swam north, going slowly, paying out line from the spool. Now that he was traveling in a straight line, he covered the bottom quickly, and in less than a minute he was in shallow water. He stopped, afraid that his tank would show above the surface.

It was clearer in the shallows. He made out the line of a branch, or root of some kind that thrust its way through the surface. It would serve. Quickly he passed the spool around it and made a knot, then he pushed the spool itself into the mud and turned.

Now to find the boat again. Cruising slowly, he headed in the general direction, rising slightly as he swam. Finally, he found the boat by its shadow and swam under it to the stern. Again orienting himself by the sun, he made sure that the boat would be between him and the south bank. He surfaced and pulled off his mask.

Scotty was swabbing the deck of the cockpit as casually as though trouble was the last thing on his mind. Rick wondered briefly if he had imagined the danger signal, or had mistaken some other sound for a signal. Then Scotty hailed him.

"Where are all the clams?"

Rick's mind raced. Obviously someone was listening. Was the someone on the boat, or ashore?

"I only found one," he called back. "I don't believe there are enough in this cove to bother about, no matter what those fishermen said."

"Did you dig deep enough?" Scotty asked.

"As deep as I could without a shovel. The mud is two feet thick down there."

"Well, you might as well come aboard. I guess if we're going to have clam chowder, we'll have to buy clams from a commercial boat."

Scotty wouldn't invite him aboard if there was any danger, Rick knew. He accepted the hand Scotty held down and got aboard.

He surveyed the situation quickly. There was no sign of any danger.

"Pretty murky down there?" Scotty asked.

"Like swimming in ink."

"We'll try again out in deep water. It should be clear near the river mouth."

"Suits me," Rick said. "I never did think we'd find clams in this cove. The mano boats dredge in deeper water than this."

"Maybe the fishermen didn't want us stirring things up where they clam. Come on in and I'll fix you some coffee. I made it while you were down below."

"Okay."

Once inside the cabin, Scotty said softly, "Two men. On the shore. One is the bodyguard. I've never seen the other one before. Both of them have rifles."

Rick considered. "They couldn't possibly know the thing—whatever it is—dropped in the water here. Or could they?"

"I don't know. Anyway, they're suspicious. Did you find anything?"

"Just as you signaled. How did you signal, by the way?"

"With the mop pail. Four taps with the bottom on the water surface. Then I filled the pail and began swabbing down."

Rick nodded. "I don't know what I found. A cylinder, maybe two inches in diameter, maybe less. Smooth. I got the fish line around it and carried the line to the shore. We'll have to come back later."

"We certainly will." Scotty's eyes sparkled. "But for now, let's up anchor and get out of here."

"How about the stake with the rope on it?"

"The tide's still coming in. It will be completely under the water at high tide. We'll have to avoid it, and warn Harris if we don't get back tonight."

An idea was beginning to form in Rick's mind. "Okay," he said. "Let's get going."

Within minutes the houseboat was on its way out of the cove, the two boys acting normally, as though no one was observing their departure. Rick saw no one on shore, and not until they were sunward from the cove entrance did he see the sparkle of sunlight on binocular lenses. Scotty had been right, as usual.



CHAPTER XII

Night Recovery

On the way back from the airport, Steve Ames listened intently to the report of the day's activities, but delayed comment until supplies had been purchased, and a dozen eggs turned into an omelet that a French chef might have praised.

Rick was eager to discuss the whole affair with Steve, but the young agent was adroit at fending off questions without being rude, and finally the boy gave up.

Over after-dinner coffee, Steve smiled at both of them. "End of today's lesson in patience, which is one virtue neither of you has developed sufficiently. Okay, where are those two pictures?"

Scotty whipped them from the breast pocket of his shirt and handed them over without comment. Steve studied them for long minutes, then went to a table and took a magnifying glass from the table drawer. He placed the pictures directly under a lamp and studied them with the aid of the magnifier.

"It is Thomas Camillion," he said finally. "Your friend Sandy Allen has a sharp eye. I wouldn't have known him, either."

That surprised Rick. Steve had never met the owner of Calvert's Favor, but because of Camillion's notorious reputation, Rick had been certain that Steve would recognize him on sight.

Steve saw the expression on Rick's face. He grinned. "You disappointed? First of all, my knowledge of Camillion is not greater than yours. I've never seen him in person, or had any reason to study him. Crime isn't JANIG's business. Second, one expects to see a duck near water, or a squirrel near a tree. Criminals are generally found near centers of crime. They're not common in historic mansions, far from large population centers, so one doesn't expect to find them there. My reasons for not recognizing Camillion, without Allen's identification, are exactly the same as yours."

"It's just that we expect you to know everything," Scotty said half-seriously.

"Then I'm glad you're learning better. Joking aside, it's interesting that Camillion should be here. It's even more interesting that his sidekick is a crooked electronics engineer or scientist. When you add flying stingarees to that combination, it totals up to something novel in criminal ideas. But what?"

"We thought you might have an idea," Rick prodded.

"Yes and no," Steve said ambiguously. "What ideas do you have?"

Rick stared at him accusingly. "Are you holding out on us? Do you know something we don't?"

"Not yet," Steve said, and grinned at their expressions. "I mean that literally. I think I may possibly know something, but the evidence isn't in yet. It's that computer run I mentioned. We should have the results tomorrow."

"All right," Rick said. He knew better than to push Steve for more information. The agent went in for speculation only when it served a purpose. With only a hint of evidence, he avoided guessing until the evidence had been checked out. "We figured out that the flying stingarees probably are balloons," Rick reported, recapitulating their conclusions of the previous evening.

Steve nodded approvingly. "Very good reasoning. Now connect up an electronics crook, Camillion, and that peculiar antenna."

"The balloons carry radio equipment," Scotty said promptly. "The antenna picks up their signals."

Steve nodded again. "That's reasonable. Now, why do the balloons carry radio equipment? And why are they launched?"

"We're like a dog chasing his tail," Rick said with a grin. "We're not getting anywhere, but we're covering plenty of ground."

"Maybe we are getting somewhere," Steve corrected. "You found something today that may be the balloon payload. You also found out that people from the mansion were interested in your activities, but didn't want to be seen. It's obvious that the object you found must be recovered. You've got a plan. I'm sure of it."

"We do," Rick agreed.

Scotty added, "First of all, we have to warn Orvil Harris. If he goes crabbing in the middle of the night, he might foul a prop on the stake we left there."

"The people in the mansion can't be suspicious of Orvil," Rick went on. "He goes crabbing there every day. They must be used to him by now. Suppose we call him, to warn him about the stake, and to see if he'll help out."

"He'll be glad to help," Scotty said.

"Help how?" Steve asked. "By providing cover?"

Rick nodded. "Exactly. Scotty and I will suit up, so our skins won't show at night, and have our Scuba equipment on. Harris could come by and take the runabout in tow with us in it. We would drop off near the creek entrance and push the runabout into the channel where it would be hidden. Then we would swim into the cove and recover the object. With two of us, it would be a cinch to find the fish line."

"If the thing is too heavy to swim with," Scotty went on, "we'll hand it into Orvil's boat. Of course we'll pull up the sapling and hand that to Orvil. If the gadget is light, we'll swim back to the runabout with it, push the runabout away from the cove into the river, and then get aboard and come home."

Rick concluded, "With Orvil's motor going, no one would hear our bubbles."

Steve had followed the plan carefully. "Fair enough," he agreed. "It's a good plan. No one will see you enter the cove, and no one will see you leave. There will be only Orvil Harris catching crabs as usual."

Scotty spoke up. "We could make one change, Steve. You could be with us, either in the water or in the runabout."

Steve shook his head. "No thanks, Scotty. I have some business of my own later tonight. You carry out your plan and I'll carry out mine."

"Is your business connected with ours?" Rick asked.

"Yes, but I'm going to follow a different line of investigation. If it brings results, we'll compare notes at breakfast."

"We could postpone recovery and help you tonight," Scotty suggested.

Steve smiled warmly. "Thanks, but no thanks. What I have to do is for a lone hand. Rick, you phone Orvil Harris and make arrangements."

Rick consulted the telephone directory and turned to Steve. "Any chance the line may be bugged?"

"I doubt it. You might ask Orvil if he's on a party line, though. If he is, be careful. If not, go ahead and talk."

Orvil Harris had a private line, so Rick described their adventure in the cove and asked for the crabber's help. Harris responded at once, as the boys had known he would.

"I'll come by at half past three. You hook on and I'll tow you to the mouth of the creek, then you cut loose. We'll fix up the details when I see you."

Rick thanked him and hung up. "All set," he reported. "But we'll get little sleep tonight."

"It's only about eight," Steve pointed out. "You could go to bed right away." He managed to say it with a straight face.

"We could," Scotty agreed. "But we won't. How about a little television tonight?"

Steve waved a hand. "Take your pick. Medical drama, crime drama, western drama."

"The purpose of television drama," Rick declared, "is to provide an escape from the real world into the world of fantasy. So no crime drama for us because that's the real world. We will watch a medical-type show."

"Western," Scotty said. "Trot-trot, bang-bang."

"Medical." Rick held out a hand dramatically. "Scalpel! Sponge! Quick, nurse, tighten the frassen-stat! The patient is going into nurbeling aspoxium!"

"Western." Scotty crouched, hand curved at his thigh. "Make your play, Brant!"

"Medical." Rick tapped an imaginary stethoscope on his palm. "I regret that you have all the symptoms of thickus headus, Mr. Scott."

Steve held up both hands. "Whoa, Mr. Scott. You too, Dr. Brant. As the only impartial participant, I will select. We will improve your minds by finding a panel show about the problems of agriculture in Basutoland."

The boys groaned.

It turned out to be an entertaining TV evening, with one good show following another, and the late show an exciting sea adventure filmed many years before the boys were born, but one of their favorites from other late-night movies. The three had no intention of staying up to watch it, but lingered for the first reel—and were lost.

It was the same with the late, late show, a horror movie so badly done that it served as a new type of comedy. By this time, all were too tired to go to bed, and by mutual consent, they watched the program to the end, then rallied in the kitchen for sandwiches and coffee.

By the time the boys had retired to the houseboat, checked their equipment, and climbed into diving suits of black neoprene with helmets and socks, Orvil Harris was coming down the creek.

Scotty checked the runabout outboard to make sure it would start easily and that there was plenty of gas, while Rick put their tanks and regulators aboard. Then, with a final farewell to Steve, the boys got aboard Orvil's boat, secured the runabout to the stern, and started off.

On the way to Swamp Creek, Rick and Scotty described their plan to the crabber. Harris slapped his thigh. "Now we're gettin' somewhere. You just lay the pole and rope up on the gunwale as I go by, and leave the rest to me. If the thing on the bottom is too heavy, I can pull it in. Got a line to put on it?"

Rick admitted they had forgotten that detail. "We can cut a length off the pole line."

"No need. Plenty of short lengths in that rope locker behind you. Take what you need."

The boys each selected a ten-foot length of half-inch nylon rope, sufficiently long for hauling the object up, if need be.

Harris asked, "Sure you can find your way underwater in the dark?"

"We have wrist compasses with luminous dials," Scotty explained.

"Good. Any danger of you comin' up under me?"

"No. We'll see the white bubbles from your prop. They'll be phosphorescent." Rick pointed to the crab boat's wake. Thousands of tiny bay creatures, most of them almost invisible bits of jelly, flashed blue white as the prop disturbed them, so that the wake twinkled as though studded with stars.

They fell silent as Harris crossed the Little Choptank, the steady beat of his motor nearly lost in the darkness. Rick could not make out details or landmarks, but Harris knew the way as well as he knew the inside of his own boat. Rick enjoyed the coolness of the night, and even the heavy scent of the salted eel the crabber used as bait.

Harris tapped each boy on the shoulder in turn, and pointed. They could barely make out the entrance to the creek. They nodded, and shook hands, then Rick pulled the runabout towline and brought the smaller boat to the crabber's stern. Scotty stepped aboard and held out a hand. Rick joined him, casting off as he embarked. In a moment they were adrift.

It took only five minutes to get their tanks in place, put on fins, and go through their routine of checking weight belt releases, making certain that the emergency valves were in the "up" position on the tanks, and ensuring that regulators were operating smoothly. Rick slipped into the water with only a small splash, and Scotty followed. They took the runabout's bow rope and swam easily and quietly.

There was no hurry. Orvil Harris would need a little time to put out his lines. He would avoid the pole they had placed; its top would be above water at this stage of the tide.

Scotty led the way to the opening into the small waterway through which they had gone to the duck blind. He found it without difficulty, and for the thousandth time Rick marveled at his pal's sure sense of position and direction, even in darkness. The boat was pushed backward into the opening and tied to a root.

Rick rinsed his mask, put it on, and slid noiselessly under the water. Scotty followed in a direct line, letting Rick pick the course, and following by the feeling of Rick's flipper wash on his cheeks.

It was like swimming in ink. Rick kept his hands out in case of unexpected underwater objects, but forged ahead at a good speed. He kept track of his own rate of progress through the water by timing the number of flutter kicks per minute. At the count of fifty he turned to the left, heading directly into the creek's mouth. He could hear the steady beat of Orvil's motor. When he estimated he had covered the proper distance, he stopped and let Scotty catch up with him. He put a hand on his pal's shoulder and pressed down, a signal to hold position. Then, very carefully, he swam to the top of the water and lifted his head above the surface. He could see the sapling a dozen yards away, slightly to his right. Orvil was putting out lines upstream, near the point where Swamp Creek widened into the cove.

Rick went under again and tapped Scotty. He headed for the pole, hands outstretched to intercept it. His left hand hit it and held. Scotty came alongside and they swam to the bottom. Both gripped the pole, put fins flat against the muddy bottom, and heaved. The pole came up without difficulty. While Scotty held it, Rick wrapped rope around it until the line was fully wound again. Orvil's motor was nearer now. Rick took one end of the pole while Scotty took the other. They operated entirely by touch; nothing was visible except the luminous dials of their compasses. The motor sound was muted in the burbling exhaust of their bubbles.

It was almost possible to stand on flipper tips with head above water. The boys thrust their heads out with care, and saw Orvil bearing down on them, peering forward anxiously. He waved when he saw the two helmeted heads. There was a slight gleam from the masks even in the darkness. As he came alongside, the boys held the pole overhead, water churning under their flippers. Orvil bent and took it, lifted it on board, and continued on his path.

The boys went under again, operating on a prearranged plan. This time they swam side by side, hands searching for the fish line. Since Rick knew the approximate position where he had tied it to the projecting stump, he led the way toward shallow water, hoping to intercept it.

The water shoaled rapidly as the boys approached the shore. Scotty's hand suddenly gripped Rick's, and Rick felt the line.

At the same instant, Rick was aware of bubbles in the water, a trail of faint phosphorescence shooting downward past his mask. Then something glanced from his tank and he heard a sharp clang like a brazen bell in his ears. The impact rolled him partly over, and as he turned, another line of phosphorescence streaked past his eyes.

The skin on his back crawled in the blazing moment of recognition. They were being shot at!



CHAPTER XIII

The Night Watchers

Scotty, who had realized they were being shot at, was pulling at Rick's arm in frantic jerks, trying to lead him back into deeper water. Rick needed no urging. His fins thrashed in the shallows as he drove desperately for the safety of the deepest part of the cove, his hands keeping contact with the bottom.

The increased pressure on his eardrums told him they had reached the sanctuary of deeper water where the velocity of bullets would be absorbed before they could strike. He was bewildered. What had happened? Who was shooting? For a moment it crossed his mind that Orvil might be doing the shooting, but he dismissed it. He had no proof that the crabber hadn't suddenly turned on them; he just didn't believe it.

Yesterday Scotty had seen watchers on the shore, presumably from Calvert's Favor. Apparently the watchers were there now. The boys had gone into shallow water, and their tanks had shown above the surface, drawing fire. It was the only reasonable explanation. Probably the night watchers had seen the pole handed up to Orvil, or had seen the faint light reflecting from their masks.

What had happened to Orvil?

One thing was certain. They couldn't stay on the bottom indefinitely.

Rick consulted his wrist compass and closed his fingers on Scotty's shoulder. He led the way toward the mouth of the cove.

Somewhere on the shore, he thought, the night gunmen were watching the line of bubbles. The boys' only hope of escaping detection had been to avoid drawing attention to themselves. Rick knew that was impossible with watchers on the shore. Watchers at four in the morning was one thing he hadn't expected. What had drawn them?

Suddenly he knew. While he, Steve, and Scotty had examined the mansion through glasses from Orvil's boat, Merlin and company, or a single guard, had been watching them. They had drawn attention not only to Orvil, but to the time of day when the guards would need to be especially alert.

Bubbles would attract the guards' attention, not only because they foamed on the surface, but because they would leave a glow of phosphorescence. How far would bubbles and glow be visible? He had a mental image of the watchers following the shoreline. They couldn't cross the creek or its mouth to where Steve's runabout was stowed, but they could shoot that far, if they could see the bubbles.

The only way for Scotty and him to escape was to eliminate the bubble track. That meant not breathing. Not breathing was possible for a short time. During the interval, they could swim into the marsh grass and use it for cover.

Rick's thoughts raced. He tried to recall the shoreline. There must be some promontory, some outcropping of grass, behind which they could hide. Perhaps the best way was simply to swim directly out from the creek mouth until distance hid the bubbles and darkness shrouded two black-covered heads.

There was a problem, though. Scotty's air tank hadn't been used until now. Rick's had, during the initial search yesterday. He estimated quickly. Less air is used at shallow depths than at deeper depths. The water depth for most of the way was shallow enough so that tank time was essentially the same as swimming on the surface. He had had at least forty-five minutes of air to begin with, and it might be stretched to fifty minutes. He probably had used no more than forty minutes of air, total. But the remaining ten minutes would not take them out into really deep water in the river itself, and then back to shore. There was not enough air to take them to Steve's place.

He had to make up his mind. Scotty, undoubtedly, was doing some fast thinking along the same lines. Their thoughts usually followed the same track in such situations. Rick touched Scotty's side and forged ahead, heading straight out. He counted his kicks, estimating distance covered. When he reached a count of three hundred he angled right, toward the north shore of the Little Choptank. They were well out of the creek now.

When the water shoaled, he found Scotty again and pressed him down; then, very gingerly, he put his head above water, half expecting to feel the shock of a bullet.

There was a fallen tree nearby. He submerged again, touched Scotty, and led the way to its shelter. A cautious survey told him they were some distance from the creek mouth, and certainly invisible behind the waterlogged trunk and its load of leaves and other debris.

He put his lips to Scotty's ear. "Wonder what happened to Orvil?"

"We've got to find out," Scotty whispered back.

"Yes, but how?"

"We go overland."

Of course! They were on the same side as the boat, and not far away. There was the stretch of marsh between the channel and the creek. They could cross that, and overlook the creek. "Let's go," Rick whispered.

They inched their way along the fallen tree to the bank, then crawled slowly into the shelter of the marsh grass. The grass grew in a narrow swath at this point, with a tangle of scrub and trees deeper inland. They kept going until the scrub concealed them, listening for sounds from the creek. There was the beat of a motor. It sounded like Orvil's boat, and Rick thought it probably was. But would Orvil continue crabbing? Again the doubt came. Had the crabber tried to kill them? He couldn't believe it.

The boys stopped and slipped off their fins. "Lead on," Rick said softly.

"Okay. When we get to the boat, we'll wade across the channel and continue right on through the marsh grass to the bank of the creek. We'd better be as quiet as possible."

"I'm with you."

Carrying their swim fins, the boys started through the dense growth, Scotty in the lead. It was hard going. Mosquitoes whined in a steady swarm around their heads, but with the neoprene suits and helmets, only their faces and hands were exposed. Each traveled with one hand outstretched to fend off branches, the other hand waving the fins to chase the insects from their faces. The outstretched hands were wiped frequently across the suits to get rid of the pests.

Rick was careful to step where Scotty stepped. When it came to silent tracking at night, the ex-Marine had few peers.

The two skirted the shore, keeping within the tree belt, until more marsh grass warned them that the water was near. The ground gave way to mud, and the mud to water. They stepped into the narrow channel up which they had gone to the blind. They now were less than two yards from the runabout. Scotty turned at once, and keeping to the water, moved upstream. Rick followed, careful not to splash. The darkness was less dense than under the trees, but he could not make out any details.

The channel ran roughly parallel to the creek, with a strip of land about thirty yards wide between the two. When Scotty estimated they were even with the cove, he left the channel and moved into the marsh grass again. Rick followed closely, careful to make no noise. In spite of their best efforts there was an occasional sucking sound as his foot or Scotty's pulled out of the muck, and there was a steady rustle of marsh grass. He hoped that the sounds were drowned out by the steady chugging of Orvil's motor.

Scotty slowed to a cautious pace and Rick knew they were approaching the creek bank. The marsh grass did not thin appreciably. Rick wondered if the night watchers could see the tassels of the grass waving as they approached, and decided that the small motion probably was invisible against the high bank of trees farther inland.

Rick stopped as Scotty turned. Soundlessly, Scotty lowered himself to the mud, then inched ahead, moving each strand of marsh grass with care. Rick followed suit, and crawled in Scotty's track until he saw the glimmer of water. Then, moving with great caution, he drew alongside his pal. They looked out into the cove through a thin screen of grass stalks.

Orvil Harris was crabbing, as unconcerned as though nothing had happened. As Rick stared, disbelieving, the crabber's net swooped.

The crab boat moved on, exposing a glow on the opposite bank. Rick sucked in his breath. He could make out the forms of two men. One was smoking a cigarette. Both carried rifles.



CHAPTER XIV

Daybreak

Rick tugged at Scotty's suit, then crawfished backward through the marsh grass until he was sure the night watchers could not see him. He stood up, and Scotty joined him. Rick motioned toward their own boat.

The boys made their way back through the swamp to the runabout in almost total silence, each busy with his own thoughts.

Orvil Harris was crabbing as though nothing had happened, while the night watchers stood in plain sight on the opposite shore. Orvil must have seen the shots fired, Rick was certain. Even if he had been looking the other way, the first shot would have caught his attention.

Or, Rick wondered, had Orvil tipped off the two guards that divers were below? If so, the game was up. Once Merlin and company knew the payload had fallen into the cove, they would be diving for it themselves, under cover of guns. Merlin undoubtedly knew that the launching the evening of the squall had gone wrong, but he couldn't know how, or where.

But somehow, Rick didn't think Orvil had been a party to the shooting. Maybe it was stubbornness, refusing to think the crabber was involved just because they liked him. Or maybe it was because the crabber had no reason for helping Merlin and his gang; at least Harris had no reason known to Rick and Scotty.

They reached the boat and conferred in whispers that were inaudible six feet away.

"Could Orvil have put the finger on us?" Scotty questioned.

Rick shrugged. "I don't want to think so, and I don't. But I have to admit it's possible."

"If he's in with them, they'll be diving for the 'what's-it' at first light."

Rick glanced at the eastern sky. It was beginning to glow with the first hint of daylight. "That's not long from now."

"How are we going to recover it first?"

Again Rick shrugged. "There's only one way. Go in and get it."

"Under those guns?"

"A diver on the bottom isn't in danger from the guns. I could find the thing again without going into the shallows. That's what made us targets before, because we took the easy way to locate the fish line by going into the shallows near where I tied the line."

"Let's see your tank," Scotty whispered.

Rick unsnapped his harness release and swung the tank around. Their probing fingers soon identified where the bullet had glanced off. There was a dent, coated with silvery metal.

"Lead," Rick said. "Part of the slug."

"Good thing it didn't rupture the tank."

Rick shuddered. "If it had, I'd have been out of air suddenly and would've had to come up. Listen, Scotty. My plan is a simple one. I'll take your tank, since you have the most air, and swim right into the cove, find the 'what's-it' and swim out again. If it's too heavy to tow far, I can at least wrestle it part of the way, and then bury it in the mud. Meanwhile, you get the boat out where it's clear and be ready to pick me up."

"They'll see your bubbles, but they can't do anything about it with rifles," Scotty pointed out. "One thing they can do, though, is jump in after you. The cove isn't so deep that a pair of good swimmers couldn't tackle you. The lung wouldn't improve your chances by much."

"Too true," Rick observed. "But what else can we try?"

Scotty thought it over. "Listen, we'll take the boat out right now. You'll have to do the diving, because you know about where the thing is, and I don't. When we get out, you go over the side. I'll run around to the river, opposite where the guards are standing, and raise a little fuss. That might draw their attention away from the cove."

"Okay." It made sense to Rick. "They'll see both of us in the boat, but they won't see me get out. Only you'd better plan our course. I have no aching desire to collect a rifle slug where it hurts."

"They may not shoot if they see we're leaving," Scotty pointed out.

"Uh-huh. And they might shoot, anyway."

"They might. But we'll be moving fast, and I'll swing that boat from side to side like a swivel-hipped fullback. Let's get going. We don't want too much daylight."

Scotty unsnapped his harness and Rick took his pal's tank and regulator. They put Rick's unit in the bottom of the runabout cockpit, along with Scotty's fins and mask. Rick put on his own fins and made sure he was ready to hit the water at a moment's notice.

Rick went to the stern of the runabout and felt down the motor leg to the prop to make sure it had not picked up any grass that might slow them down. It was clear. Scotty, meanwhile, untied the boat and slid into the driver's seat. Rick reached over the transom and pumped up the gasoline tank to ensure plenty of pressure, then he waded to the side of the boat and got into the seat next to Scotty.

"Pull us out to where the nose is almost projecting beyond the grass," Scotty whispered.

Rick did so, by grasping clumps of marsh grass and pulling the boat along. As the bow cleared the grass, Scotty punched the starter button, threw the runabout into gear, and shoved the throttle all the way forward.

The runabout jumped forward, slamming Rick back against his tank. The boat hit the shoal at the entrance and slowed for a long, breathtaking moment, then the driving prop pushed it over into deeper water. The stern went down and the bow lifted, and they were clear.

Scotty swung the boat to the right, putting its stern to the cove. Rick tensed, expecting any moment to feel the impact of a rifle bullet, either in the boat or in his own body. There was no sound other than the racing motor, and he knew it would drown out the crack of a distant rifle.

The distance from the cove entrance widened. "Get ready!" Scotty yelled. "Lay flat and be ready to roll. I'll turn so the motor is moving away from you. When I tap you, we'll be directly in line with the cove entrance."

Rick moved out of the seat, keeping low, and lay on his side along the gunwale, facing Scotty. He put the mouthpiece in place and made sure he was getting air, then pulled his mask down. He was ready. The impact with the water would be hard, at this speed, but his tank would cushion the shock. He tensed for the signal.

Scotty swung the boat to the left, held it on course for a moment, then began a shallow turn to the right. That way, the motor would be steering itself away from Rick when he went over.

The boat came abreast of the cove entrance and Scotty slapped Rick on the shoulder. Instantly Rick rolled, one hand reaching for the back of his head, the other grabbing his mask. He hit the water on his back, his hand and the tank breaking the shock of the stunning impact. He threw his legs upward, and his momentum took him under the water instantly.

The racing motor receded, leaving him in silent darkness. He rolled over into normal swimming position and consulted his wrist compass. The creek entrance ran on a course of 80 degrees. If Scotty had gauged things correctly, that course would take him into the cove. If Scotty hadn't, Rick Brant would end up on the beach like a stranded whale.

Rick considered. The boat was gone, and it was extremely unlikely anyone had seen him leave it. The turn had caused the boat to tilt, lifting the side away from him. He was certain that the guards had not seen the maneuver. That being so, and taking into account his distance from the creek entrance, he thought it would be safe to look and check his course.

He held the compass in front of his eyes, and rose to the surface. He broke through slowly and without a splash. One look was enough. He should have trusted Scotty. He was dead on course.

Rick went to the bottom and began the long swim, counting his leg strokes. He and Scotty had practiced estimating underwater distance by the number and timing of their leg strokes. It wasn't an exact method, of course, but it was practical.

There were no underwater obstacles, and the depth was great enough. Rick remembered from the chart that the entrance into the creek varied from eight to eleven feet, dropping inside the creek mouth to about seven. No bullet could harm him if he stayed on the bottom. If the night watchers fired, the bullet would be slowed by the water.

He heard the sound of a motor and recognized it as the runabout. The sound faded again. Scotty was going through some kind of maneuvers. Then, in a short time, another motor made itself felt, more than heard. The slower beat identified it as Orvil Harris's crab boat. He was nearing the cove!

Like all divers, Rick's ears were sensitive to pressure changes. Sensing when the depth lessened, he knew he had reached the cove itself. Now to find the payload—if it was a payload. His groping hands began the search.

The first foreign object he touched was a cord. It was the wrong thickness for his own line, and he felt along it until he came to a soft, round mass, and knew he was touching one of Orvil's crab baits. He grinned in spite of the mouthpiece. Wouldn't Orvil be surprised if a diver came up hanging to his bait!

He let the crab line drop and continued his search. Once, Orvil passed within a few feet of him, and Rick wondered if the crabber had noticed the air bubbles from his regulator.

Rising ground told Rick he had reached the end of the cove. He turned left and held his course for about twenty feet, then turned left again, heading back toward the cove entrance. His hands never stopped moving, probing the mud for a trace of fish line. He crossed another of Orvil's crab lines, and kept going until pressure change told him he was back in the deeper water at the creek entrance. He turned right again. A check of his compass told him he was on course.

His groping hands trailed over a thin line. He grabbed it, and stopped his flutter kick. Then, moving with care, he turned and followed the line. His pulse was faster now, and he rigidly controlled his breathing. Fast breathing wouldn't do, and he would have to be careful not to let out a sigh that would cause bubbles to gush upward in one big rush.

A hand found the end of the line and the smooth cylinder to which it was attached. Orvil passed very close, and Rick looked upward. He could see the white circle of water around the single propeller.

Now to find out what he had. His hands stroked it from one end to the other. One end was rounded. The other was a circle with an odd-shaped hole running into it. Rick poked his finger in, but couldn't feel the end of the depression. The only protuberance on the thing was a band near the rounded end. The band felt like metal, and had two rings projecting from it. The rest of the cylinder didn't feel like metal. The texture was that of a smooth plastic.

Rick lifted the object gingerly. It was hard to estimate weight under water, but he thought ten pounds would be about right. The total length was less than three feet. It would be easy to carry.

This time he needed a reciprocal compass course. It would be 260 degrees going out. He oriented himself properly, picked up the cylinder, and began the long swim back. He wondered if Merlin's guards were watching his bubbles. He had seen no sign of bullets, but he hadn't been looking for them. With Orvil's motor so near, it was likely he would not have heard the slap of a bullet on the water.

Pressure told him he was out of the cove. He breathed a little easier. Now to count leg strokes again. He looked up, and saw that the surface of the water was shining with light, the first rays of true daylight. Scotty would have no trouble finding him.

Because of the daylight, he continued on for a distance beyond where Scotty had dropped him. No use giving the guards too good a shot. Finally, exhausted, he surfaced. He lifted his mask and surveyed the scene.

Orvil Harris was still crabbing. Rick could see the boat, but the angle was wrong for him to see the crabber at work. He turned slowly in the water, and saw Scotty. The runabout was floating, motor off, about a mile away. He lifted an arm. The glint of first sunrise turned the lenses of Scotty's binoculars into a crimson eye, and Scotty waved back. In a few seconds Rick heard the motor start and saw the boat racing toward him. He kept his mouthpiece in place, and floated, waiting.



Scotty came alongside and reached down. Rick handed him the cylinder. Scotty put it on the seat without even looking at it. He gave Rick a hand and pulled him over the side. He asked anxiously, "Are you all right?"

"Done in," Rick said wearily. "But otherwise okay."

"Let's get out of here." Scotty put the runabout in gear and headed back toward Martins Creek.

Rick sat down and picked up the cylinder. There was a gob of mud still on it. He wiped it off with his hand and examined the thing. The material was fiber glass set in resin, and it was designed so the rounded nose could be removed. He didn't remove it, however. Instead he looked at the other end, down into the hole with the puzzling shape. It was like a cutout Star of David in shape, the hole gradually narrowing until its apex was almost at the other end.

The light dawned. Rick's lips formed the word. "Grain."

Scotty was watching. "What?"

"Grain," Rick said again. "This thing is a small solid-propellant rocket!"



CHAPTER XV

The Empty Boat

The Swiss torsion clock on Steve Ames's fireplace mantle read 6:49. Rick and Scotty, in slacks, shirts, and moccasins, sat in armchairs and tried to stay awake. The small rocket, cleaned and dried, rested on a newspaper on Steve's table.

"Rockoon," Rick said. "That explains the funny antenna, the presence of the electronics expert, and why the stingarees are launched."

"Not to me, it doesn't," Scotty retorted. He sipped steaming coffee. "What was that word you used? Grain?"

Rick nodded sleepily. "That's what solid rocket fuel is called. It's poured into the casing around a form. The form is withdrawn after the fuel hardens. The shape is designed to give maximum burning surface. Since the solid fuel is grainy, it's called grain."

"Logical," Scotty replied with a languid wave of his hand. "All perfectly logical. I also understand that a rockoon is a combination of a rocket and a balloon. The balloon carries the rocket up to where the air is less dense, then the rocket fires and breaks away. How does the rocket know when to fire?"

"Two ways. A barometric switch can be installed that will act at a certain altitude, or a signal can be sent from the ground."

"The antenna," Scotty said. "It can send a signal."

"Sure."

"I'm with you all the way, until you say this shows why the stingarees fly. Why send up rockoons? What's the reason?"

Rick forgot he was holding a coffee cup and waved his hand. He recovered in time to keep from spilling the hot liquid on Steve's rug. "Scientific research is usually the reason for rockoons. They carry experiments."

Scotty snorted. "Are you telling me Lefty Camillion has turned scientist?"

"Nope." Rick yawned. "I take it back. We still don't know why the stingarees fly. We only know what they are. Where do you suppose Steve is?"