Inspector Willis was more than interested in his new case. The more he thought over it, the more he realized its dramatic possibilities and the almost world-wide public interest it was likely to arouse, as well as the importance which his superiors would certainly attach to it; in other words, the influence a successful handling of it would have on his career.

He had not been idle since the day of the inquest, now a week past. To begin with he had seen Hilliard secretly, and learned at first hand all that that young man could tell him. Next he had made sure that the finger-prints found on the speaking tube were not those of Mr. Coburn, and he remained keenly anxious to obtain impressions from Captain Beamish's fingers to compare with the former. But inquiries from the port officials at Hull, made by wire on the evening of the inquest, showed that the Girondin would not be back at Ferriby for eight days. There had been no object, therefore, in his leaving London immediately, and instead he had busied himself by trying to follow up the deceased's movements in the metropolis, and learn with whom he had associated during his stay. In his search for clues he had even taken the hint from Merriman's newspaper and bought a copy of The Mystery of a Hansom Cab, but though he saw that this clever story might easily have inspired the crime, he could find from it no help towards its solution.

He had also paid a flying visit to the manager of the Hopwood Manufacturing Company in Sheffield, where Coburn had been employed. From him he had learned that Madeleine's surmise was correct, and that there had been “friction” before her father left. In point of fact a surprise audit had revealed discrepancies in the accounts. Some money was missing, and what was suspiciously like an attempt to falsify the books had taken place. But the thing could not be proved. Mr. Coburn had paid up, but though his plea that he had made a genuine clerical error had been accepted, his place had been filled. The manager expressed the private opinion that there was no doubt of his subordinate's guilt, saying also that it was well known that during the previous months Coburn had been losing money heavily through gambling. Where he had obtained the money to meet the deficit the manager did not know, but he believed someone must have come forward to assist him.

This information interested Willis keenly, supporting, as it seemed to do, his idea that Coburn was in the power of the syndicate or one of its members. If, for example, one of these men, on the lookout for helpers in his conspiracy, had learned of the cashier's predicaments it was conceivable that he might have obtained his hold by advancing the money needed to square the matter in return for a signed confession of guilt. This was of course the merest guesswork, but it at least indicated to Willis a fresh line of inquiry in case his present investigation failed.

And with the latter he was becoming exceedingly disappointed. With the exception of the facts just mentioned, he had learned absolutely nothing to help him. Mr. Coburn might as well have vanished into thin air when he left the Peveril Hotel, for all the trace he had left. Willis could learn neither where he went nor whom he met on any one of the four days he had spent in London. He congratulated himself, therefore, that on the following day the Girondin would be back at Ferriby, and he would then be able to start work on the finger-print clue.

That evening he settled himself with his pipe to think over once more the facts he had already learned. As time passed he found himself approaching more and more to the conclusion reached by Hilliard and Merriman several weeks before—that the secret of the syndicate was the essential feature of the case. What were these people doing? That was the question which at all costs he must answer.

His mind reverted to the two theories already in the field. At first sight that of brandy smuggling seemed tenable enough, and he turned his attention to the steps by which the two young men had tried to test it. At the loading end their observations were admittedly worthless, but at Ferriby they seemed to have made a satisfactory investigation. Unless they had unknowingly fallen asleep in the barrel, it was hard to see how they could have failed to observe contraband being set ashore, had any been unloaded. But he did not believe they had fallen asleep. People were usually conscious of awakening. Besides there was the testimony of Menzies, the pilot. It was hardly conceivable that this man also should have been deceived. At the same time Willis decided he must interview him, so as to form his own opinion of the man's reliability.

Another possibility occurred to him which none of the amateur investigators appeared to have thought of. North Sea trawlers were frequently used for getting contraband ashore. Was the Girondin transferring illicit cargo to such vessels while at sea?

This was a question Inspector Willis felt he could not solve. It would be a matter for the Customs Department. But he knew enough about it to understand that immense difficulties would have to be overcome before such a scheme could be worked. Firstly, there was the size of the fraud. Six months ago, according to what Miss Coburn overheard, the syndicate were making 6,800 pounds per trip, and probably, from the remarks then made, they were doing more today. And 6,800 meant—the inspector buried himself in calculations—at least one thousand gallons of brandy. Was it conceivable that trawlers could get rid of one thousand gallons every ten days—One hundred gallons a day? Frankly he thought it impossible. In fact, in the face of the Customs officers' activities, he doubted if such a thing could be done by any kind of machinery that could be devised. Indeed, the more Willis pondered the smuggling theory, the less likely it seemed to him, and he turned to consider the possibilities of Miss Coburn's SUGGESTION of false note printing.

Here at once he was met by a fact which he had not mentioned to Merriman. As it happened, the circulation of spurious Treasury notes was one of the subjects of interest to Scotland Yard at the moment. Notes were being forged and circulated in large numbers. Furthermore, the source of supply was believed to be some of the large towns in the Midlands, Leeds being particularly suspected. But Leeds was on the direct line through Ferriby, and comparatively not far away. Willis felt that it was up to him to explore to the uttermost limit all the possibilities which these facts opened up.

He began by looking at the matter from the conspirators' point of view. Supposing they had overcome the difficulty of producing the notes, how would they dispose of them?

Willis could appreciate the idea of locating the illicit press in France. Firstly, it would be obvious to the gang that the early discovery of a fraud of the kind was inevitable. Its existence, indeed, would soon become common property. But this would but slightly affect its success. It was the finding of the source of supply that mattered, and the difficulty of this was at once the embarrassment of the authorities and the opportunity of the conspirators.

Secondly, English notes were to be forged and circulated in England, therefore it was from the English police that the source of supply must be hidden. And how better could this be done than by taking it out of England altogether? The English police would look in England for what they wanted. The attention of the French police, having no false French notes to deal with, would not be aroused. It seemed to Willis that so far he was on firm ground.

The third point was that, granting the first two, some agency would be required to convey the forged notes from France to England. But here a difficulty arose. The pit-prop plan seemed altogether too elaborate and cumbrous for all that was required. Willis, as Merriman had done earlier, pictured the passenger with the padded overcoat and the double-bottomed handbag. This traveller, it seemed, would meet the case.

But did he? Would there not, with him, be a certain risk? There would be a continuous passing through Customs houses, frequent searchings of the faked suitcase. Accidents happen. Suppose the traveller held on to his suitcase too carefully? Some sharp-eyed Customs officer might become suspicious. Suppose he didn't hold on carefully enough and it were lost? Yes, there would be risks. Small, doubtless, but still risks. And the gang couldn't afford them.

As Willis turned the matter over in his mind, he came gradually to the conclusion that the elaboration of the pit-prop business was no real argument against its having been designed merely to carry forged notes. As a business, moreover, it would pay or almost pay. It would furnish a secret method of getting the notes across at little or no cost. And as a blind, Willis felt that nothing better could be devised. The scheme visualized itself to him as follows. Somewhere in France, probably in some cellar in Bordeaux, was installed the illicit printing-press. There the notes were produced. By some secret method they were conveyed to Henri when his lorry-driving took him into the city, and he in turn brought them to the clearing and handed them over to Coburn. Captain Beamish and Bulla would then take charge of them, probably hiding them on the Girondin in some place which would defy a surprise Customs examination. Numbers of such places, Willis felt sure, could be arranged, especially in the engine room. The cylinders of a duplicate set of pumps, disused on that particular trip, occurred to him as an example. After arrival at Ferriby there would be ample opportunity for the notes to be taken ashore and handed over to Archer, and Archer “could plant stuff on Old Nick himself.”

The more he pondered over it, the more tenable this theory seemed to Inspector Willis. He rose and began pacing the room, frowning heavily. More than tenable, it seemed a sound scheme cleverly devised and carefully worked out. Indeed he could think of no means so likely to mislead and delude suspicious authorities in their search for the criminals as this very plan.

Two points, however, think as he might, he could not reconcile. One was that exasperating puzzle of the changing of the lorry number plates, the other how the running of a second boat to Swansea would increase the profits of the syndicate.

But everything comes to him who waits, and at last he got an idea. What if the number of the lorry was an indication to the printers of the notes as to whether Henri was or was not in a position to take over a consignment? Would some such sign be necessary? If Henri suspected he was under observation, or if he had to make calls in unsuitable places, he would require a secret method of passing on the information to his accomplices. And if so, could a better scheme be devised than that of showing a prearranged number on his lorry? Willis did not think so, and he accepted the theory for what it was worth.

Encouraged by his progress, he next tackled his second difficulty—how the running of a second boat would dispose of more notes. But try as he would he could arrive at no conclusion which would explain the point. It depended obviously on the method of distribution adopted, and of this part of the affair he was entirely ignorant. Failure to account for this did not therefore necessarily invalidate the theory as a whole.

And with the theory as a whole he was immensely pleased. As far as he could see it fitted all the known facts, and bore the stamp of probability to an even greater degree than that of brandy smuggling.

But theories were not enough. He must get ahead with his investigation.

Accordingly next morning he began his new inquiry by sending a telegram.

“To BEAMISH, Landes Pit-Prop Syndicate, Ferriby, Hull.

“Could you meet me off London train at Paragon Station at 3.9 tomorrow re death of Coburn. I should like to get back by 4.0. If not would stay and go out to Ferriby.

“WILLIS,

“Scotland Yard.”

He travelled that same day to Hull, having arranged for the reply to be sent after him. Going to the first-class refreshment room at the Paragon, he had a conversation with the barmaid in which he disclosed his official position, and passed over a ten-shilling note on account for services about to be rendered. Then, leaving by the evening train, he returned to Doncaster, where he spent the night.

On the next day he boarded the London train which reaches Hull at 3.9. At Paragon Station he soon singled out Beamish from Merriman's description.

“Sorry for asking you to come in, Captain Beamish,” he apologized, “but I was anxious if possible to get back to London tonight. I heard of you from Miss Coburn and Mr. Merriman, both of whom read of the tragedy in the papers, and severally came to make inquiries at the Yard. Lloyd's Register told me your ship came in here, so I came along to see you in the hope that you might be able to give me some information about the dead man which might suggest a line of inquiry as to his murderer.”

Beamish replied politely and with a show of readiness and candor.

“No trouble to meet you, inspector. I had to come up to Hull in any case, and I shall be glad to tell you anything I can about poor Coburn. Unfortunately I am afraid it won't be much. When our syndicate was starting we wanted a manager for the export end. Coburn applied, there was a personal interview, he seemed suitable and he was appointed on trial. I know nothing whatever about him otherwise, except that he made good, and I may say that in the two years of our acquaintance I always found him not only pleasant and agreeable to deal with, but also exceedingly efficient in his work.”

Willis asked a number of other questions—harmless questions, easily answered about the syndicate and Coburn's work, ending up with an expression of thanks for the other's trouble and an invitation to adjourn for a drink.

Beamish accepting, the inspector led the way to the first-class refreshment room and approached the counter opposite the barmaid whose acquaintance he had made the previous day.

“Two small whiskies, please,” he ordered, having asked his companion's choice.

The girl placed the two small tumblers of yellow liquid before her customers and Willis added a little water to each.

“Well, here's yours,” he said, and raising his glass to his lips, drained the contents at a draught. Captain Beamish did the same.

The inspector's offer of a second drink having been declined, the two men left the refreshment room, still chatting about the murdered man. Ten minutes later Captain Beamish saw the inspector off in the London train. But he did not know that in the van of that train there was a parcel, labelled to “Inspector Willis, passenger to Doncaster by 4.0 p.m.,” which contained a small tumbler, smelling of whisky, and carefully packed up so as to prevent the sides from being rubbed.

The inspector was the next thing to excited when, some time later, he locked the door of his bedroom in the Stag's Head Hotel at Doncaster and, carefully unpacking the tumbler, he took out his powdering apparatus and examined it for prints. With satisfaction he found his little ruse had succeeded. The glass bore clearly defined marks of a right thumb and two fingers.

Eagerly he compared the prints with those he had found on the taxi call-tube. And then he suffered disappointment keen and deep. The two sets were dissimilar.

So his theory had been wrong, and Captain Beamish was not the murderer after all! He realized now that he had been much more convinced of its truth than he had had any right to be, and his chagrin was correspondingly greater. He had indeed been so sure that Beamish was his man that he had failed sufficiently to consider other possibilities, and now he found himself without any alternative theory to fall back on.

But he remained none the less certain that Coburn's death was due to his effort to break with the syndicate, and that it was to the syndicate that he must look for light on the matter. There were other members of it—he knew of two, Archer and Morton, and there might be more—one of whom might be the man he sought. It seemed to him that his next business must be to find those other members, ascertain if any of them were tall men, and if so, obtain a copy of their finger-prints.

But how was this to be done? Obviously from the shadowing of the members whom he knew, that was, Captain Beamish, Bulla, and Benson, the Ferriby manager. Of these, Beamish and Bulla were for the most part at sea; therefore, he thought, his efforts should be concentrated on Benson.

It was with a view to some such contingency that he had alighted at Doncaster instead of returning to London, and he now made up his mind to return on the following day to Hull and, the Girondin having by that time left, to see what he could learn at the Ferriby depot.

He spent three days shadowing Benson, without coming on anything in the slightest degree suspicious. The manager spent each of the days at the wharf until about six o'clock. Then he walked to Ferriby Station and took the train to Hull, where he dined, spent the evening at some place of amusement, and returned to the depot by a late train.

On the fourth day, as the same program seemed to be in prowess, Willis came to the conclusion that he was losing time and must take some more energetic step. He determined that if Benson left the depot in the evening as before, he would try to effect an entrance to his office and have a look through his papers.

Shortly after six, from the hedge behind which he had concealed himself, he saw Benson appear at the door in the corrugated iron fence, and depart in the direction of Ferriby. The five employees had left about an hour earlier, and the inspector believed the works were entirely deserted.

After giving Benson time to get clear away, he crept from his hiding place, and approaching the depot, tried the gate in the fence. It was locked, but few locks were proof against the inspector's prowess, and with the help of a bent wire he was soon within the enclosure. He closed the gate behind him and, glancing carefully round, approached the shed.

The door of the office was also locked, but the bent wire conquered it too, and in a couple of minutes he pushed it open, passed through, and closed it behind him.

The room was small, finished with yellow matchboarded walls and ceiling, and containing a closed roll-top desk, a table littered with papers, a vertical file, two cupboards, a telephone, and other simple office requisites. Two doors led out of it, one to the manager's bedroom, the other to the shed. Thinking that those could wait, Willis settled down to make an examination of the office.

He ran rapidly though methodically through the papers on the table without finding anything of interest. All referred to the pit-prop industry, and seemed to indicate that the business was carried on efficiently. Next he tackled the desk, picking the lock with his usual skill. Here also, though he examined everything with meticulous care, his search was fruitless.

He moved to the cupboards. One was unfastened and contained old ledgers, account books and the like, none being of any interest. The other cupboard was locked, and Willis's quick eyes saw that the woodwork round the keyhole was much scratched, showing that the lock was frequently used. Again the wire was brought into requisition, and in a moment the door swung open, revealing to the inspector's astonished gaze—a telephone.

Considerably puzzled, he looked round to the wall next the door. Yes, he had not been mistaken; there also was affixed a telephone. He crossed over to it, and following with his eye the run of the wires, saw that it was connected to those which approached the shed from across the railway.

With what, then, did this second instrument communicate? There were no other wires approaching the shed, nor could he find any connection to which it could be attached.

He examined the instrument more closely, and then he saw that it was not of the standard government pattern. It was marked “The A. M. Curtiss Co., Philadelphia, Pa.” It was therefore part of a private installation and, as such, illegal, as the British Government hold the monopoly for all telephones in the country. At least it would be illegal if it were connected up.

But was it? The wires passed through the back of the cupboard into the wall, and, looking down, Willis saw that one of the wall sheeting boards, reaching from the cupboard to the floor, had at some time been taken out and replaced with screws.

To satisfy his curiosity he took out his combination pocket knife, and deftly removing the screws, pulled the board forward. His surprise was not lessened when he saw that the wires ran down inside the wall and, heavily insulated, disappeared into the ground beneath the shed.

“Is it possible that they have a cable?” thought the puzzled man, as he replaced the loose board and screwed it fast.

The problem had to stand over, as he wished to complete his investigation of the remainder of the building. But though he searched the entire premises with the same meticulous thoroughness that he had displayed in dealing with the papers, he came on nothing else which in any way excited his interest.

He let himself out and, relocking the various doors behind him, walked to Hassle and from there returned to his hotel in Hull.

He was a good deal intrigued by his discovery of the secret telephone. That it was connected up and frequently used he was certain, both from the elaboration of its construction and from the marking round the cupboard keyhole. He wondered if he could without discovery tap the wires and overhear the business discussed. Had the wires been carried on poles the matter would have been simple, but as things were he would have to make his connection under the loose board and carry his cable out through the wall and along the shore to some point at which the receiver would be hidden—by no means an easy matter.

But in default of something better he would have tried it, had not a second discovery he made later on the same evening turned his thoughts into an entirely new channel.

It was in thinking over the probable purpose of the telephone that he got his idea. It seemed obvious that it was used for the secret side of the enterprise, and if so, would it not most probably connect the import depot of the secret commodity with that of its distribution? Ferriby wharf was the place of import, but the distribution, as the conversations overheard indicated, lay not in the hands of Benson but of Archer. What if the telephone led to Archer?

There was another point. The difficulty of laying a secret land wire would be so enormous that in the nature of things the line must be short. It must either lead, Willis imagined, to the southern bank of the estuary or to somewhere quite near.

But if both these conclusions were sound, it followed that Archer himself must be found in the immediate neighborhood. Could he learn anything from following up this idea?

He borrowed a directory of Hull and began looking up all the Archers given in the alphabetical index. There were fifteen, and of these one immediately attracted his attention. It read:

“Archer, Archibald Charles, The Elms, Ferriby.”

He glanced at his watch. It was still but slightly after ten. Taking his hat he walked to the police station and saw the sergeant on duty.

“Yes, sir,” said the man in answer to his inquiry. “I know the gentleman. He is the managing director of Ackroyd and Holt's distillery, about half-way between Ferriby and Hassle.”

“And what is he like in appearance?” Willis continued, concealing the interest this statement had aroused.

“A big man, sir,” the sergeant answered. “Tall, and broad too. Clean shaven, with heavy features, very determined looking.”

Willis had food for thought as he returned to his hotel. Merriman had been thrilled when he learned of the proximity of the distillery to the syndicate's depot, seeing therein an argument in favor of the brandy smuggling theory. This new discovery led Willis at first to take the same view, but the considerations which Hilliard had pointed out occurred to him also, and though he felt a little puzzled, he was inclined to dismiss the matter as a coincidence.

Though after his recent experience he was even more averse to jumping to conclusions than formerly, Willis could not but believe that he was at last on a hopeful scent. At all events his first duty was clear. He must find this Archibald Charles Archer, and obtain prints of his fingers.

Next morning found him again at Ferriby, once more looking southwards from the concealment of a cluster of bushes. But this time the object of his attention was no longer the syndicate's depot. Instead he focused his powerful glasses on the office of the distillery.

About nine-thirty a tall, stoutly built man strode up to the building and entered. His dress indicated that he was of the employer class, and from the way in which a couple of workmen touched their caps as he passed, Willis had no doubt he was the managing director.

For some three hours the inspector lay hidden, then he suddenly observed the tall man emerge from the building and walk rapidly in the direction of Ferriby. Immediately the inspector crept down the hedge nearer to the road, so as to see his quarry pass at close quarters.

It happened that as the man came abreast of Willis, a small two-seater motor-car coming from the direction of Ferriby also reached the same spot. But instead of passing, it slowed down and its occupant hailed the tall man.

“Hallo, Archer,” he shouted. “Can I give you a lift?”

“Thanks,” the big man answered. “It would be a kindness. I have unexpectedly to go into Hull, and my own car is out of order.”

“Run you in in quarter of an hour.”

“No hurry. If I am in by half past one it will do. I am lunching with Frazer at the Criterion at that time.”

The two-seater stopped, the big man entered, and the vehicle moved away.

As soon as it was out of sight, Willis emerged from his hiding-place, and hurrying to the station, caught the 1.17 train to Hull. Twenty minutes later he passed through the swing doors of the Criterion.

The hotel, as is well known, is one of the most fashionable in Hull, and at the luncheon hour the restaurant was well filled. Glancing casually round, Willis could see his new acquaintance seated at a table in the window, in close conversation with a florid, red-haired individual of the successful business man type.

All the tables in the immediate vicinity were occupied, and Willis could not get close by in the hope of overhearing some of the conversation, as he had intended. He therefore watched the others from a distance, and when they had moved to the lounge he followed them.

He heard them order coffee and liqueurs, and then a sudden idea came into his head. Rising, he followed the waiter through the service door.

“I want a small job done,” he said, while a ten-shilling note changed hands. “I am from Scotland Yard, and I want the finger-prints of the men who have just ordered coffee. Polish the outsides of the liqueur glasses thoroughly, and only lift them by the stems. Then when the men have gone let me have the glasses.”

He returned to the lounge, and presently had the satisfaction of seeing Archer lift his glass by the bowl between the finger and thumb of his right hand, to empty his liqueur into his coffee. Hall an hour later he was back in his hotel with the carefully packed glass.

A very few minutes sufficed for the test. The impressions showed up well, and this time the inspector gave a sigh of relief as he compared them with those of the taxi speaking-tube. They were the same. His quest was finished. Archer was the murderer of Francis Coburn.

For a minute or two, in his satisfaction, the inspector believed his work was done. He had only to arrest Archer, take official prints of his fingers, and he had all the necessary proof for a conviction. But a moment's consideration showed him that his labors were very far indeed from being over. What he had accomplished was only a part of the task he had set himself. It was a good deal more likely that the other members of the syndicate were confederates in the murder as well as in the illicit trade. He must get his hands on them too. But if he arrested Archer he would thereby destroy all chance of accomplishing the greater feat. The very essence of success lay in lulling to rest any doubts that their operations were suspect which might have entered into the minds of the members of the syndicate. No, he would do nothing at present, and he once more felt himself up against the question which had baffled Hilliard and Merriman—What was the syndicate doing? Until he had answered this, therefore, he could not rest.

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.