And how was it to be done? After some thought he came to the conclusion that his most promising clue was the secret telephone, and he made up his mind the next day he would try to find its other end, and if necessary tap the wires and listen in to any conversation which might take place.

CHAPTER 15. INSPECTOR WILLIS LISTENS IN

Inspector Willis was a good deal exercised by the question of whether or not he should have Archer shadowed. If the managing director conceived the slightest suspicion of his danger he would undoubtedly disappear, and a man of his ability would not be likely to leave many traces. On the other hand Willis wondered whether even Scotland Yard men could shadow him sufficiently continuously to be a real safeguard, without giving themselves away. And if that happened he might indeed arrest Archer, but it would be good-bye to any chance of getting his confederates.

After anxious thought he decided to take the lesser risk. He would not bring assistants into the matter, but would trust to his own skill to carry on the investigation unnoticed by the distiller.

Though the discovery of Archer's identity seemed greatly to strengthen the probability that the secret telephone led to him, Willis could not state this positively, and he felt it was the next point to be ascertained. The same argument that he had used before seemed to apply—that owing to the difficulty of wiring, the point of connection must be close to the depot. Archer's office was not more than three hundred yards away, while his house, The Elms, was over a mile. The chances were therefore in favor of the former.

It followed that he must begin by searching Archer's office for the other receiver, and he turned his attention to the problem of how this could best be done.

And first, as to the lie of the offices. He called at the Electric Generating Station, and having introduced himself confidentially to the manager in his official capacity, asked to see the man whose business it was to inspect the lights of the distillery. From him he had no difficulty in obtaining a rough plan of the place.

It appeared that the offices were on the first floor, fronting along the line, Archer's private office occupying the end of the suite and the corner of the building nearest to the syndicate's wharf, and therefore to Ferriby. The supervisor believed that it had two windows looking to the front and side respectively, but was not sure.

That afternoon Inspector Willis returned to the distillery, and secreting himself in the same hiding place as before, watched until the staff had left the building. Then strolling casually along the lane, he observed that the two telephone wires which approached across the fields led to the third window from the Ferriby end of the first floor row.

"That'll be the main office," he said to himself, "but there will probably be an extension to Archer's own room. Now I wonder—"

He looked about him. The hedge bounding the river side of the lane ran up to the corner of the building. After another hasty glance round Willis squeezed through and from immediately below scrutinized the side window of the managing director's room. And then he saw something which made him chuckle with pleasure.

Within a few inches of the architrave of the window there was a down-spout, and from the top of the window to the spout he saw stretching what looked like a double cord. It was painted the same color as the walls, and had he not been looking out specially he would not have seen it. A moment's glance at the foot of the spout showed him his surmise was correct. Pushed in behind it and normally concealed by it were two insulated wires, which ran down the wall from the window and disappeared into the ground with the spout.

"Got it first shot," thought the inspector delightedly, as he moved away so as not to attract the attention of any chance onlooker.

Another idea suddenly occurred to him and, after estimating the height and position of the window, he turned and ran his eye once more over his surroundings. About fifty yards from the distillery, and behind the hedge fronting the lane, stood the cottage which Hilliard and Merriman had noticed. It was in a bad state of repair, having evidently been unoccupied for a long time. In the gable directly opposite the managing director's office was a broken window. Willis moved round behind the house, and once again producing his bent wire, in a few moments had the back door open. Slipping inside, he passed through the damp-smelling rooms and up the decaying staircase until he reached the broken window. From it, as he had hoped, he found he had a good view into the office.

He glanced at his watch. It was ten minutes past seven.

"I'll do it tonight," he murmured, and quietly leaving the house, he hurried to Ferriby Station and so to Hull.

Some five hours later he left the city again, this time by motor. He stopped at the end of the lane which ran past the distillery, dismissed the vehicle, and passed down the lane. He was carrying a light, folding ladder, a spade, a field telephone, a coil of insulated wire, and some small tools.

The night was very dark. The crescent moon would not rise for another couple of hours, and a thick pall of cloud cut off all light from the stars. A faint wind stirred the branches of the few trees in the neighborhood and sighed across the wide spaces of open country. The inspector walked slowly, being barely able to see against the sky the tops of the hedges which bounded the lane. Except for himself no living creature seemed to be abroad.

Arrived at his destination, Willis felt his way to the gap in the hedge which he had used before, passed through, and with infinite care raised his ladder to the window of Archer's office. He could not see the window, but he checked the position of the ladder by the measurements from the hedge. Then he slowly ascended.

He found he had gauged his situation correctly, and he was soon on the sill of the window, trying with his knife to push back the hasp. This he presently accomplished, and then, after an effort so great that he thought he would be beaten, he succeeded in raising the sash. A minute later he was in the room.

His first care was to pull down the thick blinds of blue holland with which the windows were fitted. Then tip-toeing to the door, he noiselessly shot the bolt in the lock.

Having thus provided against surprise, he began his investigation. There in the top corner of the side window were the wires. They followed the miter of the window architrave—white-enameled to match—and then, passing down for a few inches at the outside of the moldings, ran along the picture rail round the room, concealed in the groove behind it. Following in the same way the miter of the architrave, they disappeared though a door in the back wall of the office.

Willis softly opened the door, which was not locked, and peered into a small store, evidently used for filing. The wires were carried down the back of the architrave molding and along the top of the wainscoting, until finally they disappeared into the side of one of a series of cupboards which lined the wall opposite the door. The cupboard was locked, but with the help of the bent wire it soon stood open and Willis, flashing in a beam from his electric torch, saw with satisfaction that he had attained at least one of his objects. A telephone receiver similar to that at the syndicate's depot was within.

He examined the remaining contents of the room, but found nothing of interest until he came to the door. This was solidly made and edged with rubber, and he felt sure that it would be almost completely sound-proof. It was, moreover, furnished with a well-oiled lock.

"Pretty complete arrangement," Willis thought as he turned back to the outer office. Here he conducted another of his meticulous examinations, but unfortunately with a negative result.

Having silently unlocked the door and pulled up the blinds, he climbed out on the window sill and closed the window. He was unable to refasten the hasp, and had therefore to leave this evidence of his visit, though he hoped and believed it would not be noticed.

Lifting down the ladder, he carried it to the cottage and hid it therein. Part of his task was done, and he must wait for daylight to complete the remainder.

When some three hours later the coming dawn had made objects visible, he again emerged armed with his tools and coil of insulated wire. Digging a hole at the bottom of the down-pipe, he connected his wires just below the ground level to those of the telephone. Then inserting his spade along the face of the wall from the pipe to the hedge, he pushed back the adjoining soil, placed the wires in the narrow trench thus made, and trod the earth back into place. When the hole at the down-spout had been filled, practically no trace remained of the disturbance.

The ground along the inside of the hedge being thickly grown over with weeds and grass, he did not think it necessary to dig a trench for the wire, simply bedding it beneath the foliage. But he made a spade cut across the sward from the hedge to the cottage door, sank in the wire and trod out the cut. Once he had passed the tiny cable beneath the front door he no longer troubled to hide it but laid it across the floors and up the airs to the broken window. There he attached the field receiver, affixing it to his ear so as to be ready for eventualities.

It was by this time half past six and broad daylight, but Willis had seen no sign of life and he believed his actions had been unobserved. He ate a few sandwiches, then lighting his pipe, lay down on the floor and smoked contentedly.

His case at last was beginning to prosper. The finding of Coburn's murderer was of course an event of outstanding importance, and now the discovery of the telephone was not only valuable for its own sake, but was likely to bring in a rich harvest of information from the messages he hoped to intercept. Indeed he believed he could hardly fail to obtain from this source a definite indication of the nature and scope of the conspiracy.

About eight o'clock he could see from his window a number of workmen arrive at the distillery, followed an hour later by a clerical staff. After them came Archer, passing from his car to the building with his purposeful stride. Almost immediately he appeared in his office, sat down at his desk, and began to work.

Until nearly midday Willis watched him going through papers, dictating letters, and receiving subordinates. Then about two minutes to the hour he saw him look at his watch, rise, and approach the door from the other office, which was in Willis's line of vision behind the desk. He stooped over the lock as if turning the key, and then the watcher's excitement rose as the other disappeared out of sight in the direction of the filing room.

Willis was not disappointed. Almost immediately he heard the faint call of the tiny buzzer, and then a voice—Archer's voice, he believed, from what he had heard in the hotel lounge called softly, "Are you there?"

There was an immediate answer. Willis had never heard Benson speak, but he presumed that the reply must be from him.

"Anything to report?" Archer queried.

"No. Everything going on as usual."

"No strangers poking round and asking questions?"

"And no traces of a visitor while you were away?"

"None."

"Good. It's probably a false alarm. Beamish may have been mistaken."

"I hope so, but he seemed very suspicious of that Scotland Yard man—said he was sure he was out for more than he pretended. He thought he was too easily satisfied with the information he got, and that some of his questions were too foolish to be genuine."

Inspector Willis sat up sharply. This was a blow to his dignity, and he felt not a little scandalized. But he had no time to consider his feelings. Archer was speaking again.

"I think we had better be on the safe side. If you have the slightest suspicion don't wait to report to me. Wire at once to Henri at the clearing this message—take it down so that there'll be no mistake—'Six hundred four-foot props wanted. If possible send next cargo.' Got that? He will understand. It is our code for 'Suspect danger. Send blank cargoes until further notice.' Then if a search is made nothing will be found, because there won't be anything there to find."

"Very good. It's a pity to lose the money, but I expect you're right."

"We can't take avoidable risks. Now about yourself. I see you brought no stuff up last night?"

"Couldn't. I had a rotten bilious attack. I started, but had to go back to bed again. Couldn't stand."

"Better?"

"Yes, all right now, thanks."

"Then you'll bring the usual up tonight?"

"Certainly."

"Very well. Now, what about ten forty-five for tomorrow?"

"Right."

The switch snapped, and in a few seconds the watcher saw Archer return to his office, bend for a moment over the lock of the door, then reseat himself at his desk.

"I've got them now," he thought triumphantly. "I've got them at last. Tonight I'll take them red-handed in whatever they're doing." He smiled in anticipation. "By Jove," he went on, "it was lucky they sent nothing up last night, or they would have taken me red-handed, and that might have been the end of me!"

He was greatly impressed by the excellence of the telephone scheme. There was nothing anywhere about it to excite suspicion, and it kept Archer in touch with the illicit undertaking, while enabling him to hold himself absolutely aloof from all its members. If the rest of the organization was as good, it was not surprising that Hilliard, and Merriman had been baffled.

But the puzzle was now solved, the mystery at an end. That night, so Willis assured himself, the truth would be known.

He remained in his hiding place all day, until, indeed, he had watched the workers at the distillery leave and the gray shadows of evening had begun to descend. Then he hid the telephone and wire in a cupboard, stealthily left the house, and after a rapid glance round hurried along the lane towards Ferriby.

He caught the 6.57 train to Hull, and in a few minutes was at the police station. There he saw the superintendent, and after a little trouble got him to fall in with the plan which he had devised.

As a result of their conference a large car left the city shortly before nine, in which were seated Inspector Willis and eight picked constables in plain clothes. They drove to the end of the Ferriby Lane, where the men dismounted, and took cover behind some shrubs, while the car returned towards Hull.

It was almost, but not quite dark. There was no moon, but the sky was clear and the stars were showing brightly. A faint air, in which there was already a touch of chill, sighed gently through the leaves, rising at intervals almost to a breeze, then falling away again to nothing. Lights were showing here and there—yellow gleams from unshaded windows, signal lamps from the railway, navigation lights from the river. Except for the sound of the retreating car and the dull roar of a distant train, the night was very still, a night, in fact, pre-eminently suitable for the inspector's purpose.

The nine men moved silently down the lane at intervals of a few minutes, their rubber-shod feet making no sound on the hard surface. Willis went first, and as the others reached him he posted them in the positions on which he had previously decided. One man took cover behind the hedge of the lane, a short distance on the distillery side of the wharf, another behind a pile of old material on the railway at the same place, a third hid himself among some bushes on the open ground between the railway and the river, while a fourth crept as near to the end of the wharf as the tide would allow, so as to watch approaches from the water. When they were in position, Willis felt convinced no one could leave the syndicate's depot for the distillery without being seen.

The other four men he led on to the distillery, placing them in a similar manner on its Ferriby side. If by some extraordinary chance the messenger with the "stuff" should pass the first cordon, the second, he was satisfied, would take him. He left himself free to move about as might appear desirable.

The country was extraordinarily deserted. Not one of the nine men had seen a living soul since they left their motor, and Willis felt certain that his dispositions had been carried out in absolute secrecy.

He crossed the fence on to the railway. By climbing half-way up the ladder of a signal he was able to see the windows of the shed over the galvanized fence. All were in darkness, and he wondered if Benson had gone on his customary expedition into Hull.

To satisfy himself on this point he hid beneath a wagon which was standing on the siding close to the gate in the fence. If the manager were returning by his usual train he would be due in a few minutes, and Willis intended to wait and see.

It was not long before a sharp footfall told that someone was coming along the lane. The unknown paused at the stile, climbed over; and, walking more carefully across the rails, approached the door. Willis, whose eyes were accustomed to the gloom, could make out the dim form of a man, showing like a smudge of intensified blackness against the obscurity beyond. He unlocked the door, passed through, slammed it behind him, and his retreating steps sounded from within. Finally another door closed in the distance and silence again reigned.

Willis crawled out from beneath his truck and once more climbed the signal ladder. The windows of Benson's office were now lighted up, but the blinds being drawn, the inspector could see nothing within.

After about half an hour he observed the same phenomenon as Hilliard and Merriman had witnessed—the light was carried from the office to the bedroom, and a few minutes later disappeared altogether.

The ladder on which he was standing appearing to Willis to offer as good an observation post as he could hope to get, he climbed to the little platform at the top, and seating himself, leaned back against the timber upright and continued his watch.

Though he was keenly interested by his adventure, time soon began to drag. It was cramped on the little seat, and he could not move freely for fear of falling off. Then to his dismay he began to grow sleepy. He had of course been up all the previous night, and though he had dozed a little during his vigil in the deserted house, he had not really rested. He yawned, stretched himself carefully, and made a determined effort to overcome his drowsiness.

He was suddenly and unexpectedly successful. He got the start of his life, and for a moment he thought an earthquake had come. The signal post trembled and swayed while with a heavy metallic clang objects moved through the darkness near his head. He gripped the rail, and then he laughed as he remembered that railway signals were movable. This one had just been lowered for a train.

Presently it roared past him, enveloping him in a cloud of steam, which for an instant was lit bright as day by the almost white beam that poured out of the open door of the engine firebox. Then, the steam clearing, there appeared a strip of faintly lit ground on either side of the flying carriage roofs; it promptly vanished; red tail Lamps appeared, leaping away; there was a rattle of wheels over siding connections, and with a rapidly decreasing roar the visitation was past. For a moment there remained the quickly moving spot of lighted steam, then it too vanished. Once again the signal post swayed as the heavy mechanism of the arm dropped back into the "on" position, and then all was once more still.

The train had effectually wakened Willis, and he set himself with a renewed vigor to this task. Sharply he watched the dark mass of the shed with its surrounding enclosure, keenly he listened for some sound of movement within. But all remained dark and silent.

Towards one in the morning he descended from his perch and went the round of his men. All were alert, and all were unanimous that no one had passed.

The time dragged slowly on. The wind had risen somewhat and clouds were banking towards the north-west. It grew colder, and Willis fancied there must be a touch of frost.

About four o'clock he went round his pickets for the second time. He was becoming more and more surprised that the attempt had been delayed so long, and when some two hours later the coming dawn began to brighten the eastern sky and still no sign had been observed, his chagrin waxed keen. As the light increased, he withdrew his men to cover, and about seven o'clock, when it was no longer possible that anything would be attempted, he sent them by ones and twos to await their car at the agreed rendezvous.

He was more disappointed at the failure of his trap than he would have believed possible. What, he wondered, could have happened? Why had the conspirators abandoned their purpose? Had he given himself away? He went over in his mind every step he had taken, and he did not see how any one of them could have become known to his enemies, or how any of his actions could have aroused their suspicions. No; it was not, he felt sure, that they had realized their danger. Some other quite accidental circumstance had intervened to cause them to postpone the transfer of the "stuff" for that night But what extraordinary hard luck for him! He had obtained his helpers from the superintendent only after considerable trouble, and the difficulty of getting them again would be much greater. And not the least annoying thing was that he, a London man, one, indeed, of the best men at the Yard, had been made to look ridiculous in the eyes of these provincial police!

Dog-tired and hungry though he was, he set his teeth and determined that he would return to the cottage in the hope of learning the reason of his failure from the conversation which he expected would take place between Archer and Benson at a quarter to eleven that day.

Repeating, therefore, his proceedings of the previous morning, he regained his point of vantage at the broken window. Again he watched the staff arrive, and again observed Archer enter and take his place at his desk. He was desperately sleepy, and it required all the power of his strong will to keep himself awake. But at last his perseverance was rewarded, and at 10.45 exactly he saw Archer bolt his door and disappear towards the filing room. A moment later the buzzer sounded.

"Are you there?" once again came in Archer's voice, followed by the astounding phrase, "I see you brought up that stuff last night."

"Yes, I brought up two hundred and fifty," was Benson's amazing reply.

Inspector Willis gasped. He could scarcely believe his ears. So he had been tricked after all! In spite of his carefully placed pickets, in spite of his own ceaseless watchfulness, he had been tricked. Two hundred and fifty of the illicit somethings had been conveyed, right under his and his men's noses, from the depot to the distillery. Almost choking with rage and amazement he heard Archer continue:

"I had a lucky deal after our conversation yesterday, got seven hundred unexpectedly planted. You may send up a couple of hundred extra tonight if you like."

"Right. I shall," Benson answered, and the conversation ceased.

Inspector Willis swore bitterly as he lay back on the dusty floor and pillowed his head on his hands. And then while he still fumed and fretted, outraged nature asserted herself and he fell asleep.

He woke, ravenously hungry, as it was getting dusk, and he did not delay long in letting himself out of the house, regaining the lane, and walking to Ferriby Station. An hour later he was dining at his hotel in Hull.



CHAPTER 16. THE SECRET OF THE SYNDICATE

A night's rest made Willis once more his own man, and next morning he found that his choking rage had evaporated, and that he was able to think calmly and collectedly over the failure of his plans.

As he reconsidered in detail the nature of the watch he had kept, he felt more than ever certain that his cordons had not been broken through. No one, he felt satisfied, could have passed unobserved between the depot and the distillery.

And in spite of this the stuff had been delivered. Archer and Benson were not bluffing to put him off the scent. They had no idea they were overheard, and therefore had no reason to say anything except the truth.

How then was the communication being made? Surely, he thought, if these people could devise a scheme, he should be able to guess it. He was not willing to admit his brain inferior to any man's.

He lit his pipe and drew at it slowly as he turned the question over in his mind. And then a possible solution occurred to him. What about a subterranean connection? Had these men driven a tunnel?

Here undoubtedly was a possibility. To drive three hundred yards of a heading large enough for a stooping man to pass through, would be a simple matter to men who had shown the skill of these conspirators. The soil was light and sandy, and they could use without suspicion as much timber as they required to shore up their work. It was true they would have to pass under the railway, but that again was a matter of timbering.

Their greatest difficulty, he imagined, would be in the disposal of the surplus earth. He began to figure out what it would mean. The passageway could hardly be less than four feet by five, to allow for lining, and this would amount to about two yards of material to the yard run, or say six hundred or seven hundred cubic yards altogether. Could this have been absorbed in the filling of the wharf? He thought so. The wharf was a large structure, thirty yards by thirty at least and eight or nine feet high; more than two thousand cubic yards of filling would have been required for it. The disposal of the earth, therefore, would have presented no difficulty. All that came out of the tunnel could have gone into the wharf three times over.

A tunnel seemingly being a practical proposition, he turned his attention to his second problem. How could he find out whether or not it had been made?

Obviously only from examination at one or other end. If it existed it must connect with cellars at the depot and the distillery. And of these there could be no question of which he ought to, search. The depot was not only smaller and more compact, but it was deserted at intervals. If he could not succeed at the syndicate's enclosure he would have no chance at the larger building.

It was true he had already searched it without result, but he was not then specially looking for a cellar, and with a more definite objective he might have better luck. He decided that if Benson went up to Hull that night he would have another try.

He took an afternoon train to Ferriby, and walking back towards the depot, took cover in the same place that he had previously used. There, sheltered by a hedge, he watched for the manager's appearance.

The weather had, from the inspector's point of view, changed for the worse. The sunny days had gone, and the sky was overladen with clouds. A cold wind blew in gustily from the south-east, bringing a damp fog which threatened every minute to turn to rain, and flecking the lead-colored waters of the estuary with spots of white. Willis shivered and drew up his collar higher round his ears as he crouched behind the wet bushes.

"Confound it," he thought, "when I get into that shed I shall be dripping water all over the floor."

But he remained at his post, and in due course he was rewarded by seeing Benson appear at the door in the fence, and after locking it behind him, start off down the railway towards Ferriby.

As before, Willis waited until the manager had got clear away, then slipping across the line, he produced his bent wire, opened the door, and five minutes later stood once more in the office.

From the nature of the case it seemed clear that the entrance to the cellar, if one existed, would be hidden. It was therefore for secret doors or moving panels that he must look.

He began by ascertaining the thickness of all the walls, noting the size of the rooms so as to calculate those he could not measure directly. He soon found that no wall was more than six inches thick, and none could therefore contain a concealed opening.

This narrowed his search. The exit from the building could only be through a trap-door in the floor.

Accordingly he set to work in the office, crawling torch in hand along the boards, scrutinizing the joints between them for any that were not closed with dust, feeling for any that might be loose. But all to no purpose. The boards ran in one length across the floor and were obviously firmly nailed down on fixed joists.

He went to the bedroom, rolling aside the mats which covered the floor and moving the furniture back and forwards. But here he had no better result.

The remainder of the shed was floored with concrete, and a less meticulous examination was sufficient to show that the surface was unbroken. Nor was there anything either on the wharf itself or in the enclosure behind the shed which could form a cover to a flight of steps.

Sorely disappointed, Willis returned once more to the office, and sitting down, went over once again in his mind what he had done, trying to think if there was a point on the whole area of the depot which he had overlooked. He could recall none except the space beneath a large wardrobe in the next room which, owing to its obvious weight, he had not moved.

"I suppose I had better make sure," he said to himself, though he did not believe so massive a piece of furniture could have been pulled backwards and forwards without leaving scratches on the floor.

He returned to the bedroom. The wardrobe was divided into two portions, a single deep drawer along the bottom, and above it a kind of large cupboard with a central door. He seized its end. It was certainly very heavy; in fact, he found himself unable to move it.

He picked up his torch and examined the wooden base. And then his interest grew, for he found it was strongly stitch-nailed to the floor.

Considerably mystified, he tried to open the door. It was locked, and though with his wire he eventually shot back the bolt, the trouble he had, proved that the lock was one of first quality. Indeed, it was not a cupboard lock screwed to the inside of the door as might have been expected, but a small-sized mortice lock hidden in the thickness of the wood, and the keyhole came through to the inside; just the same arrangement as is usual in internal house doors.

The inside of the wardrobe revealed nothing of interest. Two coats and waistcoats, a sweater, and some other clothes were hanging from hooks at the back. Otherwise the space was empty.

"Why," he wondered as he stood staring in, "should it be necessary to lock up clothes like these?"

His eyes turned to the drawer below, and he seized the handles and gave a sharp pull. The drawer was evidently locked. Once again he produced his wire, but for the first time it failed him. He flashed a beam from his lamp into the hole, and then he saw the reason.

The hole was a dummy. It entered the wood but did not go through it. It was not connected to a lock.

He passed the light round the edges of the drawer. If there was no lock to fasten it why had he been unable to open it? He took out his penknife and tried to push the blade into the surrounding space. It would not penetrate, and he saw that there was no space, but merely a cut half an inch deep in the wood. There was no drawer. What seemed a drawer was merely a blind panel.

Inspector Willis grew more and more interested. He could not see why all that space should be wasted, as it was clear from the way in which the wardrobe was finished that economy in construction had not been the motive.

Once again he opened the door of the upper portion, and putting his head inside passed the beam of the lamp over the floor. This time he gave a little snort of triumph. The floor did not fit tight to the sides. All round was a space of some eighth of an inch.

"The trap-door at last," he muttered, as he began to feel about for some hidden spring. At last, pressing down on one end of the floor, he found that it sank and the other end rose in the air, revealing a square of inky blackness out of which poured a stream of cold, damp air, and through which he could hear, with the echoing sound peculiar to vaults, the splashing and churning of the sea.

His torch revealed a flight of steps leading down into the darkness. Having examined the pivoted floor to make sure there was no secret catch which could fasten and imprison him below, he stepped on to the ladder and began to descend. Then the significance of the mortice lock in the wardrobe door occurred to him, and he stopped, drew the door to behind him, and with his wire locked it. Descending farther he allowed the floor to drop gently into place above his head, thus leaving no trace of his passage.

He had by this time reached the ground, and he stood flashing his torch about on his surroundings. He was in a cellar, so low in the roof that except immediately beneath the stairs he could not stand upright. It was square, some twelve feet either way, and from it issued two passages, one apparently running down under the wharf, the other at right angles and some two feet lower in level, leading as if towards the distillery. Down the center of this latter ran a tiny tramway of about a foot gauge, on which stood three kegs on four-wheeled frames. In the upper side of each keg was fixed a tun-dish, to the under side a stop-cock. Two insulated wires came down through the ceiling below the cupboard in which the telephone was installed, and ran down the tunnel towards the distillery.

The walls and ceiling of both cellar and passages were supported by pit-props, discolored by the damp and marked by stains of earthy water which had oozed from the spaces between. They glistened with moisture, but the air, though cold and damp, was fresh. That and the noise of the waves which reverberated along the passage under the wharf seemed to show that there was an open connection to the river.

The cellar was empty except for a large wooden tun or cask which reached almost to the ceiling, and a gunmetal hand pump. Pipes led from the latter, one to the tun, the other along the passage under the wharf. On the side of the tun and connected to it at top and bottom was a vertical glass tube protected by a wooden casing, evidently a gauge, as beside it was a scale headed "gallons," and reading from 0 at the bottom to 2,000 at the top. A dark-colored liquid filled the tube up to the figure 1,250. There was a wooden spigot tap in the side of the tun at floor level, and the tramline ran beneath this so that the wheeled kegs could be pushed below it and filled.

The inspector gazed with an expression of almost awe on his face.

"Lord!" he muttered. "Is it brandy after all?"

He stooped and smelled the wooden tap, and the last doubt was removed from his mind.

He gave vent to a comprehensive oath. Right enough it was hard luck! Here he had been hoping to bring off a forged note coup which would have made his name, and the affair was a job for the Customs Department after all! Of course a pretty substantial reward would be due to him for his discovery, and there was his murder case all quite satisfactory, but forged notes were more in his line, and he felt cheated out of his due.

But now that he was so far he might as well learn all he could. The more complete the case he gave in, the larger the reward. Moreover, his own curiosity was keenly aroused.

The cellar being empty save for the tun, the pump, and the small tramway and trucks, he turned, and flashing his light before him, walked slowly along the passage down which ran the pipe. He was, he felt sure, passing under the wharf and heading towards the river.

Some sixty feet past the pump the floor of the passage came to an abrupt end, falling vertically as by an enormous step to churning waters of the river some six feet below. At first in the semi-darkness Willis thought he had reached the front of the wharf, but he soon saw he was still in the cellar. The roof ran on at the same level for some twenty feet farther, and the side walls, here about five feet apart, went straight down from it into the water. Across the end was a wall, sloping outwards at the bottom and made of horizontal pit-props separated by spaces of two or three inches. Willis immediately realized that these props must be those placed behind the inner or raking row of piles which supported the front of the wharf.

Along one side wall for its whole length was nailed a series of horizontal laths twelve inches apart. What their purpose was he did not know, but he saw that they made a ladder twenty feet wide, by which a man could work his way from the passage to the end wall and reach the water at any height of the tide.

Above this ladder was an object which at first puzzled the inspector, then as he realized its object, it became highly illuminating. On a couple of brackets secured to the wall lay a pipe of thin steel covered with thick black baize, and some sixteen feet long by an inch in diameter. Through it ran the light copper pipe which was connected at its other end to the pump. At the end of the passage this pipe had several joints like those of a gas bracket, and was folded on itself concertina-wise.

The inspector stepped on to the ladder and worked his way across it to the other end of the steel pipe, close by the end wall. The copper pipe protruded and ended in a filling like the half of a union. As Willis gazed he suddenly grasped its significance.

The side of the Girondin, he thought, would lie not more than ten feet from where he was standing. If at night someone from within the cellar were to push the end of the steel tube out through one of the spaces between the horizontal timbers of the end wall, it could be inserted into a porthole, supposing one were just opposite. The concertina joints would make it flexible and allow it to extend, and the baize covering would prevent its being heard should it inadvertently strike the side of the ship. The union on the copper tube could then be fixed to some receptacle on board, the brandy being pumped from the ship to the tun.

And no outsider could possibly be any the wiser! Given a dark night and careful operators, the whole thing would be carried out invisibly and in absolute silence.

Now Willis saw the object of the peculiar construction of the front of the wharf. It was necessary to have two lines of piles, so that the deck between might overshadow and screen from view the openings between the horizontal beams at the front of the cellar. He stood marvelling at the ingenuity of the plan. No wonder Hilliard and Merriman had been baffled.

But if he were to finish his investigations, he must no longer delay. He worked back across the side of the cellar, regained the passage, and returned to the pump-room. Then turning into the other passage, he began to walk as quickly as possible along it.

The tunnel was barely four feet high by three wide, and he found progress very tiring. After a slight curve at the mouth it ran straight and almost dead level. Its construction was the same as that of the cellar, longitudinal timber lining supported behind verticals and lintels spaced about six feet apart. When he had gone about two hundred yards it curved sharply to the left, ran heavily timbered for some thirty yards in the new direction, and then swung round to the right again.

"I suppose the railway crosses here," Willis thought, as he passed painfully round the bends.

The sweat stood in drops on his forehead when he reached the end, and he breathed a sigh of relief as he realized he could once more stand upright and stretch his cramped back. He found himself in another cellar, this time about six feet by twelve. The tramway ran along it, stopping at the end wall. The place was otherwise empty, save for a wooden grating or tun-dish with a hinged lid which was fixed between the rails near the entrance. The telephone wires, which had followed the tunnel all the way, here vanished into the roof.

Willis concluded he must be standing beneath some part of the distillery, and a very little thought was required to make clear to him the raison d'etre of what he saw. He pictured the kegs being pushed under the tap of the large tun in the pump-room and filled with brandy pumped in from the Girondin. In imagination he saw Benson pushing his loaded trucks through the tunnel—a much easier thing to do than to walk without something to step over—stopping them one by one over the grating and emptying the contents therein. No doubt that grating was connected to some vat or tun buried still deeper beneath the distillery, in which the brandy mingled with the other brandy brought there by more legitimate means, and which was sold without documentary evidence of its surprising increase in bulk.

It was probable, thought Willis, that some secret door must connect the chamber in which he stood with the distillery, but a careful search revealed no trace of any opening, and he was forced to the conclusion that none existed. Accordingly, he turned and began to retrace his steps through the tunnel.

The walk back seemed even longer and more irksome than his first transit, and he stopped here and there and knelt down in order to straighten his aching back. As he advanced, the booming sound of the waves, which had died down to a faint murmur at the distillery, grew louder and louder. At last he reached the pump-cellar, and was just about to step out of the tunnel when his eye caught the flicker of a light at the top of the step-ladder. Someone was coming down!

Willis instantly snapped off his own light, and for the fraction of a second he stood transfixed, while his heart thumped and his hand slid round to his revolver pocket. Breathlessly he watched a pair of legs step on to the ladder and begin to descend the steps.

Like a flash he realized what he must do. If this was Benson coming to "take up stuff," to remain in the tunnel meant certain discovery. But if only he could, reach the passage under the wharf he might be safe. There was nothing to bring Benson into it.

But to cross the cellar he must pass within two feet of the ladder, and the man was half-way down. For a moment it looked quite hopeless, then unexpectedly he got his chance. The man stopped to lock the wardrobe door. When he had finished, Willis was already across the cellar and hurrying down the other passage. Fortunately the noise of the waves drowned all other sounds.

By the time the unknown had reached the bottom of the ladder, Willis had stepped on to the cross laths and was descending by them. In a moment he was below the passage level. He intended, should the other approach, to hide beneath the water in the hope that in the darkness his head would not be seen.

But the light remained in the cellar, and Willis raised himself and cautiously peeped down the passage. Then he began to congratulate himself on what he had just been considering his misfortune. For, watching there in the darkness, he saw Benson carry out the very operations he had imagined were performed. The manager wheeled the kegs one by one beneath the great barrel, filled them from the tap, and then, setting his lamp on the last of the three, pushed them before him down the tunnel towards the distillery.

Inspector Willis waited until he judged the other would be out of sight, then left his hiding-place and cautiously returned to the pump-room. The gauge now showed 1,125 gallons, and he noted that 125 gallons was, put up per trip. He rapidly ascended the steps, passed out through the wardrobe, and regained the bedroom. A few minutes later he was once more out on the railway.

He had glanced at his watch in the building and found that it was but little after ten. Benson must therefore have returned by an earlier train than usual. Again the inspector congratulated himself that events had turned out as they had, for though he would have had no fear of his personal safety had he been seen, premature discovery might have allowed the other members of the gang to escape.

The last train for Hull having left, he started to walk the six miles to the city. The weather had still further changed for the worse, and now half a gale of wind whirled round him in a pandemonium of sound and blew blinding squalls of rain into his eyes. In a few moments he was soaked to the skin, and the buffeting of the wind made his progress slow. But he struggled on, too well pleased by the success of his evening's work to mind the discomfort.

And as he considered the affair on the following morning he felt even more satisfied. He had indeed done well! Not only had he completed what he set out to do—to discover the murderer of Coburn—but he had accomplished vastly more. He had brought to light one of the greatest smuggling conspiracies of modern times. It was true he had not followed up and completed the case against the syndicate, but this was not his business. Smuggling was not dealt with by Scotland Yard. It was a matter for the Customs Department. But if only it had been forged notes! He heaved a sigh as he thought of the kudos which might have been his.

But when he had gone so far, he thought he might as well make certain that the brandy was discharged as he imagined. He calculated that the Girondin would reach Ferriby on the following day, and he determined to see the operation carried out.

He followed the plan of Hilliard and Merriman to the extent of hiring a boat in Hull and sculling gently down towards the wharf as dusk fell. He had kept a watch on the river all day without seeing the motor ship go up, but now she passed him a couple of miles above the city. He turned inshore when he saw her coming, lest Captain Beamish's binoculars might reveal to him a familiar countenance.

He pulled easily, timing himself to arrive at the wharf as soon as possible after dark. The evening was dry, but the south-easterly wind still blew cold and raw, though not nearly so strongly as on the night of his walk.

There were a couple of lights on the Girondin, and he steered by these till the dark mass of her counter, looming up out of the night, cut them off. Slipping round her stern, as Hilliard had done in the River Lesque, he unshipped his oars and guided the boat by his hands into the V-shaped space between the two rows of piles fronting the wharf. As he floated gently forward he felt between the horizontal props which held back the filling until he came to a vacant space, then knowing he was opposite the cellar, he slid the boat back a few feet, tied her up, and settled down to wait.

Though sheltered from the wind by the hull, it was cold and damp under the wharf. The waves were lapping among the timbers, and the boat moved uneasily at the end of her short painter. The darkness was absolute—an inky blackness unrelieved by any point of light. Willis realized that waiting would soon become irksome.

But it was not so very long before the work began. He had been there, he estimated, a couple of hours when he saw, not ten feet away, a dim circle of light suddenly appear on the Girondin's side. Someone had turned on a faint light in a cabin whose open porthole was immediately opposite the cellar. Presently Willis, watching breathlessly, saw what he believed was the steel pipe impinge on and enter the illuminated ring. It remained projecting into the porthole for some forty minutes, was as silently withdrawn, the porthole was closed, a curtain drawn across it, and the light turned up within. The brandy had been discharged.

The thing had been done inaudibly, and invisibly to anyone on either wharf or ship. Marvelling once more at the excellence and secrecy of the plan, Willis gently pushed his boat out from among the piles and rowed back down the river to Hull. There he tied the boat up, and returning to his hotel, was soon fast asleep.

In spite of his delight at the discovery, he could not but realize that much still remained to be done. Though he had learned how the syndicate was making its money, he had not obtained any evidence of the complicity of its members in the murder of Coburn.

Who, in addition to Archer, could be involved? There were, of course, Beamish, Bulla, Benson, and Henri. There was also a man, Morton, whose place in the scheme of things had not yet been ascertained. He, Willis realized, must be found and identified. But were these all? He doubted it. It seemed to him that the smuggling system required more helpers than these. He now understood how the brandy was got from the ship to the distillery, and he presumed it was loaded at the clearing in the same manner, being brought there in some unknown way by the motor lorries. But there were two parts of the plan of which nothing was yet known. Firstly, where was the brandy obtained from originally, and, secondly, how was it distributed from the distillery? It seemed to Willis that each of these operations would require additional accomplices. And if so, these persons might also have been implicated in Coburn's death.

He thought over the thing for three solid hours before coming to a decision. At the end of that time he determined to return to London and, if his chief approved, lay the whole facts before the Customs Departments of both England and France, asking them to investigate the matter in their respective countries. In the meantime he would concentrate on the question of complicity in the murder.

He left Hull by an afternoon train, and that night was in London.

CHAPTER 17. "ARCHER PLANTS STUFF"

Willis's chief at the Yard was not a little impressed by his subordinate's story. He congratulated the inspector on his discovery, commended him for his restraint in withholding action against Archer until he had identified his accomplices, and approved his proposals for the further conduct of the case. Fortified by this somewhat unexpected approbation, Willis betook himself forthwith to the headquarters of the Customs Department and asked to see Hilliard.

The two men were already acquainted. As has been stated, the inspector had early called at Hilliard's rooms and learned all that the other could tell him of the case. But for prudential reasons they had not met since.

Hilliard was tremendously excited by the inspector's news, and eagerly arranged the interview with his chief which Willis sought. The great man was not engaged, and in a few minutes the others were shown into his presence.

"We are here, sir," Willis began, when the necessary introductions had been made, "to tell you jointly a very remarkable story. Mr. Hilliard would doubtless have told you his part long before this, had I not specially asked him not to. Now, sir, the time has come to put the facts before you. Perhaps as Mr. Hilliard's story comes before mine in point of time, he should begin."

Hilliard thereupon began. He told of Merriman's story in the Rovers' Club, his own idea of smuggling based on the absence of return cargoes, his proposition to Merriman, their trip to France and what they learned at the clearing. Then he described their visit to Hull, their observations at the Ferriby wharf, the experiment carried out with the help of Leatham, and, finally, what Merriman had told him of his second visit to Bordeaux.

Willis next took up the tale and described the murder of Coburn, his inquiries thereinto and the identification of the assassin, and his subsequent discoveries at Ferriby, ending up by stating the problem which still confronted him, and expressing the hope that the chief in dealing with the smuggling conspiracy would co-operate with him in connection with the murder.

The latter had listened with an expression of amazement, which towards the end of the inspector's statement changed to one of the liveliest satisfaction. He gracefully congratulated both men on their achievements, and expressed his gratification at what had been discovered and his desire to co-operate to the full with the inspector in the settling up of the case.

The three men then turned to details. To Hilliard's bitter disappointment it was ruled that, owing to his being known to at least three members of the gang, he could take no part in the final scenes, and he had to be content with the honor of, as it were, a seat on the council of war. For nearly an hour they deliberated, at the end of which time it had been decided that Stopford Hunt, one of the Customs Department's most skillful investigators, should proceed to Hull and tackle the question of the distribution of the brandy. Willis was to go to Paris, interest the French authorities in the Bordeaux end of the affair, and then join Hunt in Hull.

Stopford Hunt was an insignificant-looking man of about forty. All his characteristics might be described as being of medium quality. He was five feet nine in height, his brown hair was neither fair nor dark, his dress suggested neither poverty nor opulence, and his features were of the type known as ordinary. In a word, he was not one whose appearance would provoke a second glance or who would be credited with taking an important part in anything that might be in progress.

But for his job these very peculiarities were among his chief assets. When he hung about in an aimless, loafing way, as he very often did, he was overlooked by those whose actions he was so discreetly watching, and where mere loafing would look suspicious, he had the inestimable gift of being able to waste time in an afraid and preoccupied manner.

That night Willis crossed to Paris, and next day he told his story to the polite chief of the French Excise. M. Max was almost as interested as his English confrere, and readily promised to have the French end of the affair investigated. That same evening the inspector left for London, going on in the morning to Hull.

He found Hunt a shrewd and capable man of the world, as well as a pleasant and INTERESTING companion.

They had engaged a private sitting-room at their hotel, and after dinner they retired thither to discuss their plan of campaign.

"I wish," said Willis, when they had talked for some moments, "that you would tell me something about how this liquor distribution business is worked. It's outside my job, and I'm not clear on the details. If I understood I could perhaps help you better."

Hunt nodded and drew slowly at his pipe.

"The principle of the thing," he answered, "is simple enough, though in detail it becomes a bit complicated. The first thing we have to remember is that in this case we're dealing, not with distillers, but with rectifiers. Though in loose popular phraseology both businesses are classed under the term 'distilling,' in reality there is a considerable difference between them. Distillers actually produce the spirit in their buildings, rectifiers do not. Rectifiers import the spirit produced by distillers, and refine or prepare it for various specified purposes. The check required by the Excise authorities is therefore different in each case. With rectifiers it is only necessary to measure the stuff that goes into and comes out of the works. Making due allowance for variation during treatment, these two figures will balance if all is right."

Willis nodded, and Hunt resumed.

"Now, the essence of all fraud is that more stuff goes out of the works than is shown on the returns. That is, of course, another way of saying that stuff is sold upon which duty has not been paid. In the case of a rectifying house, where there is no illicit still, more also comes in than is shown. In the present instance you yourself have shown how the extra brandy enters. Our job is to find out how it leaves."

"That part of it is clear enough anyway," Willis said with a smile. "But brandy smuggling is not new. There must surely be recognized ways of evading the law?"

"Quite. There are. But to follow them you must understand how the output is measured. For every consignment of stuff that leaves the works a permit or certificate is issued and handed to the carrier who removes it. This is a kind of way-bill, and of course a block is kept for the inspection of the surveying officer. It contains a note of the quantity of stuff, date and hour of starting, consignee's name and other information, and it is the authority for the carrier to have the liquor in his possession. An Excise officer may stop and examine any dray or lorry carrying liquor, or railway wagon, and the driver or other official must produce his certificate so that his load may be checked by it. All such what I may call surprise examinations, together with the signature of the officer making them, are recorded on the back of the certificate. When the stuff is delivered, the certificate is handed over with it to the consignee. He signs it on receipt. It then becomes his authority for having the stuff on his premises, and he must keep it for the Excise officer's inspection. Do you follow me so far?"

"Perfectly."

"The fraud, then, consists in getting more liquor away from the works than is shown on the certificates, and I must confess it is not easy. The commonest method, I should think, is to fill the kegs or receptacles slightly fuller than the certificate shows. This is sometimes done simply by putting extra stuff in the ordinary kegs. It is argued that an Excise officer cannot by his eye tell a difference of five or six per cent; that, for example, twenty-six gallons might be supplied on a twenty-five gallon certificate without anyone being much the wiser. Variants of this method are to use slightly larger kegs, or, more subtly, to use the normal sized kegs of which the wood at the ends has been thinned down, and which therefore when filled to the same level hold more, while showing the same measure with a dipping rod. But all these methods are risky. On the suspicion the contents of the kegs are measured and the fraud becomes revealed."

Willis, much interested, bent forward eagerly as the other, after a pause to relight his pipe, continued:

"Another common method is to send out liquor secretly, without a permit at all. This may be done at night, or the stuff may go through an underground pipe, or be hidden in innocent looking articles such as suitcases or petrol tins. The pipe is the best scheme from the operator's point of view, and one may remain undiscovered for months, but the difficulty usually is to lay it in the first instance.

"A third method can be used only in the case of rectifiers and it illustrates one of the differences between rectifiers and distillers. Every permit for the removal of liquor from a distillery must be issued by the excise surveyor of the district, whereas rectifiers can issue their own certificates. Therefore in the case of rectifiers there is the possibility of the issuing of forged or fraudulent certificates. Of course this is not so easy as it sounds. The certificates are supplied in books of two hundred by the Excise authorities, and the blocks must be kept available for the supervisor's scrutiny. Any certificates can be obtained from the receivers of the spirit and compared with the blocks. Forged permits are very risky things to work with, as all genuine ones bear the government watermark, which is not easy to reproduce. In fact, I may say about this whole question of liquor distribution generally, that fraud has been made so difficult that the only hope of those committing it is to avoid arousing suspicion. Once suspicion is aroused, discovery follows almost as a matter of course."

"That's hopeful for us," Willis smiled.

"Yes," the other answered, "though I fancy this case will be more difficult than most. There is another point to be taken into consideration which I have not mentioned, and that is, how the perpetrators of the frauds are going to get their money. In the last resort it can only come in from the public over the counters of the licensed premises which sell the smuggled spirits. But just as the smuggled liquor cannot be put through the books of the house selling it, so the money received for it cannot be entered either. This means that someone in authority in each licensed house must be involved. It also carries with it a SUGGESTION, though only a SUGGESTION, the houses in question are tied houses. The director of a distillery company would have more hold on the manager of their own tied houses than over an outsider."

Again Willis nodded without replying, and Hunt went on:

"Now it happens that these Ackroyd & Holt people own some very large licensed houses in Hull, and it is to them I imagine, that we should first direct our attention."

"How do you propose to begin?"

"I think we must first find out how the Ferriby liquor is sent to these houses. By the way, you probably know that already. You watched the distillery during working hours, didn't you?"

The inspector admitted it.

"Did you see any lorries?"

"Any number; large blue machines. I noticed them going and coming in the Hull direction loaded up with barrels."

Hunt seemed pleased.

"Good," he commented. "That's a beginning anyway. Our next step must be to make sure that all these lorries carry certificates. We had better begin tomorrow."

Willis did not quite see how the business was to be done, but he forbore to ask questions, agreeing to fall in with his companion's arrangements.

These arrangements involved the departure from their hotel by taxi at six o'clock the next morning. It was not fully light as they whirled out along the Ferriby road, but the sky was clear and all the indications pointed to a fine day.

They dismounted at the end of the lane leading to the works, and struck off across the fields, finally taking up their position behind the same thick hedge from which Willis had previously kept watch.

They spent the whole of that day, as well as of the next two, in their hiding-place, and at the end of that time they had a complete list of all lorries that entered or left the establishment during that period. No vehicles other than blue lorries appeared, and Hunt expressed himself as satisfied that if the smuggled brandy was not carried by them it must go either by rail or at night.

"We can go into those other contingencies later if necessary," he said, "but on the face of it I am inclined to back the lorries. They supply the tied houses in Hull, which would seem the obvious places for the brandy to go, and, besides, railway transit is too well looked after to attract the gang. I think we'll follow this lorry business through first on spec."

"I suppose you'll compare the certificate blocks with the list I made?" Willis asked.

"Of course. That will show if all carry certificates. But I don't want to do that yet. Before alarming them I want to examine the contents of a few of the lorries. I think we might do that tomorrow."

The next morning, therefore, the two detectives again engaged a taxi and ran out along the Ferriby road until they met a large blue lorry loaded with barrels and bearing on its side the legend "Ackroyd & Holt Ltd, Licensed Rectifiers." When it had lumbered past on its way to the city, Hunt called to the driver and ordered him to follow it.

The chase led to the heart of the town, ending in a street which ran parallel to the Humber Dock. There the big machine turned in to an entry.

"The Anchor Bar," Hunt said, in satisfied tones. "We're in luck. It's one of the largest licensed houses in Hull."

He jumped out and disappeared after the lorry, Willis following. The vehicle had stopped in a yard at the back of the great public house, where were more barrels than the inspector ever remembered having seen together, while the smell of various liquors hung heavy in the air. Hunt, having shown his credentials, demanded the certificate for the consignment. This was immediately produced by the driver, scrutinized, and found in order. Hunt then proceeded to examine the consignment itself, and Willis was lost in admiration at the rapidity as well as the thoroughness of his inspection. He tested the nature of the various liquids, measured their receptacles, took drippings in each cask, and otherwise satisfied himself as to the quality and quantity. Finally he had a look over the lorry, then expressing himself satisfied, he endorsed the certificate, and with a few civil words to the men in charge, the two detectives took their leave.

"That's all square anyway," Hunt remarked, as they reentered their taxi. "I suppose we may go and do the same thing again."

They did. Three times more on that day, and four times on the next day they followed Messrs. Ackroyd & Holt's lorries, in every instance with the same result. All eight consignments were examined with the utmost care, and all were found to be accurately described on the accompanying certificate. The certificates themselves were obviously genuine, and everything about them, so far as Hunt could see, was in order.

"Doesn't look as if we are going to get it that way," he commented, as late that second evening they sat once more discussing matters in their private sitting-room.

"Don't you think you have frightened them into honesty by our persistence?" Willis queried.

"No doubt," the other returned. "But that couldn't apply to the first few trips. They couldn't possibly have foretold that we should examine those consignments yesterday, and today I expect they thought their visitation was over. But we have worked it as far as it will go. We shall have to change our methods."

The inspector looked his question and Hunt continued:

"I think tomorrow I had better go out to the works and have a look over these certificate blocks. But I wonder if it would be well for you to come? Archer has seen you in that hotel lounge, and at all events he has your description."

"I shall not go," Willis decided. "See you when you get back."

Hunt, after showing his credentials, was received with civility at Messrs. Ackroyd & Holt's. When he had completed the usual examination of their various apparatus he asked for certain books. He took them to a desk, and sitting down, began to study the certificate blocks.

His first care was to compare the list of outward lorries which he and Willis had made with the blocks for the same period. A short investigation convinced him that here also everything was in order. There was a certificate for every lorry which had passed out, and not only so, but the number of the lorry, the day and hour at which it left and the load were all correct so far as his observations had enabled him to check them. It was clear that here also he had drawn blank, and for the fiftieth time he wondered with a sort of rueful admiration how the fraud was being worked.

He was idly turning over the leaves of the blocks, gazing vacantly at the lines of writing while he pondered his problem when his attention was attracted to a slight difference of color in the ink of an entry on one of the blocks. The consignment was a mixed one, containing different kinds of spirituous liquors. The lowest entry was for three twenty-five gallon kegs of French brandy. This entry was slightly paler than the remain order.

At first Hunt did not give the matter serious thought. The page had evidently been blotted while the ink was wet, and the lower items should therefore naturally be the fainter. But as he looked more closely he saw that this explanation would not quite meet the case. It was true that the lower two or three items above that of the brandy grew gradually paler in proportion to their position down the sheet, and to this rule Archer's signature at the bottom was no exception. In these Hunt could trace the gradual fading of color due to the use of blotting paper. But he now saw that this did not apply to the brandy entry. It was the palest of all—paler even than Archer's name, which was below it.

He sat staring at the sheet, whistling softly through his teeth and with his brow puckered into a frown, as he wondered whether the obvious SUGGESTION that the brandy item had been added after the sheet had been completed, was a sound deduction. He could think of no other explanation, but he was loath to form a definite opinion on such slight evidence.

He turned back through the blocks to see if they contained other similar instances, and as he did so his interest grew. Quite a number of the pages referring to mixed consignment had for their last item kegs of French brandy. He scrutinized these entries with the utmost care. A few seemed normal enough, but others showed indications which strengthened his suspicions. In three more the ink was undoubtedly paler than the remainder of the sheet, in five it was darker, while in several others the handwriting appeared slightly different—more upright, more sloping, more heavily or more lightly leaned on. When Hunt had examined all the instances he could find stretching over a period of three months, he was convinced that his deduction was correct. The brandy items had been written at a different time from the remainder, and this could only mean that they had been added after the certificate was complete.

His interest at last keenly aroused, he began to make an analysis of the blocks in question in the hope of finding some other peculiarity common to them which might indicate the direction in which the solution might lie.

And first as to the consignees. Ackroyd & Holt evidently supplied a very large number of licensed houses, but of these the names of only five appeared on the doubtful blocks. But these five were confined to houses in Hull, and each was a large and important concern.

"So far, so good," thought Hunt, with satisfaction. "If they're not planting their stuff in those five houses, I'm a Dutchman!"

He turned back to the blocks and once again went through them. This time he made an even more suggestive discovery. Only one lorry-man was concerned in the transport of the doubtful consignments. All the lorries in question had been in charge of a driver called Charles Fox.

Hunt remembered the man. He had driven three of the eight lorries Hunt himself had examined, and he had been most civil when stopped, giving the investigator all possible assistance in making his inspection. Nor had he at any time betrayed embarrassment. And now it seemed not improbable that this same man was one of those concerned in the fraud.

Hunt applied himself once again to a study of the blocks, and then he made a third discovery, which, though he could not at first see its drift, struck him nevertheless as being of importance. He found that the faked block was always one of a pair. Within a few pages either in front of or behind it was another block containing particulars of a similar consignment, identical, in fact, except that the brandy item was missing.

Hunt was puzzled. That he was on the track of the fraud he could not but believe, but he could form no idea as to how it was worked. If he were right so far, the blocks had been made out in facsimile in the first instance, and later the brandy item had been added to one of each pair. Why? He could not guess.

He continued his examination, and soon another INTERESTING fact became apparent. Though consignments left the works at all hours of the day, those referred to by the first one of each between the hours of four and five. Further, the number of minutes past one and past four were always identical on each pair. That showed the brandy item was nearly always the later of the two, but occasionally the stuff had gone with the one o'clock trip.

Hunt sat in the small office, of which he had been given undisturbed possession, pondering over his problem and trying to marshal the facts that he had learned in such a way as to extract their inner meaning. As far as he could follow them they seemed to show that three times each day driver Charles Fox took a lorry of various liquors into Hull. The first trip was irregular, that is, he left at anything between seven-thirty and ten-thirty a.m., and his objective extended over the entire city. The remaining two trips were regular. Of these the first always left between one and two and the second the same number of minutes past four; both were invariably to the same one of the five large tied houses already mentioned; the load of each was always identical except that one—generally the second—had some kegs of brandy additional, and, lastly, the note of this extra brandy appeared always to have been added to the certificate after the latter had been made out.

Hunt could make nothing of it. In the evening he described his discoveries to Willis, and the two men discussed the affair exhaustively, though still without result.

That night Hunt could not sleep. He lay tossing from side to side and racking his brains to find a solution. He felt subconsciously that it was within his reach, and yet he could not grasp it.

It was not far from dawn when a sudden idea flashed into his mind, and he lay thrilled with excitement as he wondered if at last he held the clue to the mystery. He went over the details in his mind, and the more he thought over his theory the more likely it seemed to grow.

But how was he to test it? Daylight had come before he saw his way; but at last he was satisfied, and at breakfast he told Willis his idea and asked his help to carry out his plan.

"You're not a photographer, by any chance?" he asked.

"I'm not A1, but I dabble a bit at it."

"Good. That will save some trouble."

They called at a photographic outfitter's, and there, after making a deposit, succeeded in hiring two large-size Kodaks for the day. With these and a set of climbing irons they drove out along the Ferriby road, arriving at the end of the lane to the works shortly after midday. There they dismissed their taxi.

As soon as they were alone their actions became somewhat bewildering to the uninitiated. Along one side of the road ran a seven-foot wall bounding the plantation of a large villa. Over this Willis, with the help of his friend, clambered. With some loose stones he built himself a footing at the back, so that he could just look over the top. Then having focused his camera for the middle of the road, he retired into obscurity behind his defences.

His friend settled to his satisfaction, Hunt buckled on the climbing irons, and crossing the road, proceeded to climb a telegraph pole which stood opposite the lane. He fixed his camera to the lower wires—carefully avoiding possible short-circuitings—and having focused it for the center of the road, pulled a pair of pliers from his pocket and endeavored to simulate, the actions of a lineman at work. By the time these preparations were complete it was close on one o'clock.

Some half-hour later a large blue lorry came in sight bearing down along the lane. Presently Hunt was able to see that the driver was Fox. He made a prearranged sign to his accomplice behind the wall, and the latter, camera in hand, stood up and peeped over. As the big vehicle swung slowly round into the main road both men from their respective positions photographed it. Hunt, indeed, rapidly changing the film, took a second view as the machine retreated down the road towards Hull.

When it was out of sight, Hunt descended and with some difficulty climbed the wall to his colleague. There in the shade of the thick belt of trees both men lay down and smoked peacefully until nearly four o'clock. Then once more they took up their respective positions, watched until about half an hour later the lorry again passed out and photographed it precisely as before. That done, they walked to Hassle station, and took the first train to Hull.

By dint of baksheesh they persuaded the photographer to develop their films there and then, and that same evening they had six prints.

As it happened they turned out exceedingly good photographs. Their definition was excellent, and each view included the whole of the lorry. The friends found, as Hunt had hoped and intended, that owing to the height from which the views had been taken, each several keg of the load showed out distinctly. They counted them. Each picture showed seventeen.

"You see?" cried Hunt triumphantly. "The same amount of stuff went out on each load! We shall have them now, Willis!"

Next day Hunt returned to Ferriby works ostensibly to continue his routine inspection. But in three minutes he had seen what he wanted. Taking the certificate book, he looked up the blocks of the two consignments they had photographed, and he could have laughed aloud in his exultation as he saw that what he had suspected was indeed the fact. The two certificates were identical except that to the second an item of four kegs of French brandy had been added! Hunt counted the barrels. The first certificate showed thirteen and the last seventeen.

"Four kegs of brandy smuggled out under our noses yesterday," he thought delightedly. "By Jove! but it's a clever trick. Now to test the next point."

He made an excuse for leaving the works, and returning to Hull, called at the licensed house to which the previous afternoon's consignment had been dispatched. There he asked to see the certificates of the two trips. On seeing his credentials these were handed up without demur, and he withdrew with them to his hotel.

"Come," he cried to Willis, who was reading in the lounge, "and see the final act in the drama."

They retired to their private room, and there Hunt spread the two certificates on the table. Both men stared at them, and Hunt gave vent to a grunt of satisfaction.

"I was right," he cried delightedly. "Look here! Why I can see it with the naked eye!"

The two certificates were an accurate copy of their blocks. They were dated correctly, both bore Fox's name as driver, and both showed consignments of liquor, identical except for the additional four kegs of brandy on the second. There was, furthermore, no sign that this had been added after the remainder. The slight lightening in the color towards the bottom of the sheet, due to the use of blotting paper, was so progressive as almost to prove the whole had been written at the same time.

The first certificate was timed 1.15 p.m., the second 4.15 p.m., and it was to the 4 of this second hour that Hunt's eager finger pointed. As Willis examined it he saw that the lower strokes were fainter than the remainder. Further, the beginning of the horizontal stroke did not quite join the first vertical stroke.

"You see?" Hunt cried excitedly. "That figure is a forgery. It was originally a 1, and the two lower strokes have been added to make it a 4. The case is finished!"

Willis was less enthusiastic.

"I'm not so sure of that," he returned cautiously. "I don't see light all the way through. Just go over it again, will you?"

"Why to me it's as clear as daylight," the other asserted impatiently. "See here. Archer decides, let us suppose, that he will send out four kegs, or one hundred gallons, of the smuggled brandy to the Anchor Bar. What does he do? He fills out certificates for two consignments each of which contains an identical assortment of various liquors. The brandy he shows on one certificate only. The blocks are true copies of the certificates except that the brandy is not entered on either. The two blocks he times for a quarter past one and past four respectively, but both certificates he times for a quarter past one. He hands the two certificates to Fox. Then he sends out on the one o'clock lorry the amount of brandy shown on one of the certificates."

Hunt paused and looked interrogatively at his friend, then, the latter not replying, he resumed:

"You follow now the position of affairs? In the office is Archer with his blocks, correctly filled out as to time but neither showing the brandy. On the one o'clock lorry is Fox, with one hundred gallons of brandy among his load. In his pocket are the two certificates, both timed for one o'clock, one showing the brandy and the other not."

The inspector nodded as Hunt again looked at him.

"Now suppose," the latter went on, "that the one o'clock lorry gets through to its destination unchallenged, and the stuff is unloaded. The manager arranges that the four kegs of brandy will disappear. He takes over the certificate which does not show brandy, signs it, and the transaction is complete. Everything is in order, and he has got four kegs smuggled in."

"Good," Willis interjected.

"On the other hand, suppose the one o'clock trip is held up by an exciseman. This time Fox produces the other certificate, the one which shows the brandy. Once again everything is in order, and the Excise officer satisfied. It is true that on this occasion Fox has been unable to smuggle out his brandy, and on that which he carries duty must be paid, but this rare contingency will not matter to him as long as his method of fraud remains concealed."

"Seems very sound so far."

"I think so. Let us now consider the four o'clock trip. Fox arrives back at the works with one of the two certificates still in his pocket, and the make up of his four o'clock load depends on which it is. He attempts no more smuggling that day. If his remaining certificate shows brandy he carries brandy, if not, he leaves it behind. In either case his certificate is in order if an Excise officer holds him up. That is, when he has at tended to one little point. He has to add two strokes to the 1 of the hour to make it into a 4. The ease of doing this explains why these two hours were chosen. Is that all clear?"

"Clear, indeed, except for the one point of how the brandy item is added to the correct block."

"Obviously Archer does that as soon as he learns how the first trip has got on. If the brandy was smuggled out on the first trip, it means that Fox is holding the brandy-bearing certificate for the second, and Archer enters brandy on his second block. If, on the contrary, Fox has had his first load examined, Archer will make his entry on the first block."

"The scheme," Willis declared, "really means this. If Archer wants to smuggle out one hundred gallons of brandy, he has to send out another hundred legitimately on the same day? If he can manage to send out two hundred altogether then one hundred will be duty clear, but in any case he must pay on one hundred?"

"That's right. It works out like that."

"It's a great scheme. The only weak point that I can see is that an Excise officer who has held up one of the trips might visit the works and look at the certificate block before Archer gets it altered."

Hunt nodded.

"I thought of that," he said, "and it can be met quite easily. I bet the manager telephones Archer on receipt of the stuff. I am going into that now. I shall have a note kept at the Central of conversations to Ferriby. If Archer doesn't get a message by a certain time, I bet he assumes the plan has miscarried for that day and fills in the brandy on the first block."