The consideration which had thus suddenly occurred to Inspector Willis was the extraordinary importance of the fact that the tall traveller had spoken through the tube to the driver. He marveled how he could have overlooked its significance. To speak through a taxi tube one must hold up the mouthpiece, and that mouthpiece is usually made of vulcanite or some similar substance. What better surface, Willis thought delightedly but anxiously, could be found for recording finger-prints? If only the tall man had made the blunder of omitting to wear gloves, he would have left evidence which might hang him! And he, Willis, like the cursed imbecile that he was, had missed the point! Goodness only knew if he was not already too late. If so, he thought grimly, it was all up with his career at the Yard.

He ran to the telephone. A call to the Yard advised him that the taxi driver, on being informed he was no longer required, had left with his vehicle. He rapidly rang up the man's employers, asking them to stop the cab directly they came in touch with it, then hurrying out of the hotel, he hailed a taxi and drove to the rank on which the man was stationed.

His luck was in. There were seven vehicles on the stand, and his man, having but recently arrived, had only worked up to the middle of the queue. The sweat was standing in large drops on Inspector Willis's brow as he eagerly asked had the tube been touched since leaving Scotland Yard, and his relief when he found he was still in time was overwhelming. Rather unsteadily he entered the vehicle and ordered the driver to return to the Yard.

On arrival he was not long in making his test. Sending for his finger-print apparatus, he carefully powdered the vulcanite mouthpiece, and he could scarcely suppress a cry of satisfaction when he saw shaping themselves before his eyes three of the clearest prints he had ever had the good fortune to come across. On one side of the mouthpiece was the mark of a right thumb, and on the other those of a first and second finger.

“Lord!” he muttered to himself, “that was a near thing. If I had missed it, I could have left the Yard for good and all. It's the first thing the Chief would have asked about.”

His delight was unbounded. Here was as perfect and definite evidence as he could have wished for. If he could find the man whose fingers fitted the marks, that would be the end of his case.

He left the courtyard intending to return to the Peveril and resume the tracing of Miss Coburn, but before he reached the door of the great building he was stopped. A gentleman had called to see him on urgent business connected with the case.

It was Merriman—Merriman almost incoherent with excitement and distress. He still carried the newspaper in his hand, which had so much upset him. Willis pulled forward a chair, invited the other to be seated, and took the paper. The paragraph was quite short, and read:

“A tragedy which recalls the well-known detective novel The Mystery of the Hansom Cab occurred last evening in one of the most populous thoroughfares in London. It appears that about eight o'clock two men engaged a taxi in Piccadilly to take them to King's Cross. Near the Oxford Street end of Tottenham Court Road the driver was ordered to stop. One of the men alighted, bade good-night to his companion, and told the driver to proceed to King's Cross, where his friend would settle up. On reaching the station there was no sign of the friend, and a search revealed him lying dead in the taxi with a bullet wound in his heart. From papers found on the body the deceased is believed to be a Mr. Francis Coburn, but his residence has not yet been ascertained.”

Inspector Willis laid down the paper and turned to his visitor.

“You are interested in the case, sir?” he inquired.

“I knew him, I think,” Merriman stammered. “At least I know someone of the name. I—”

Willis glanced keenly at the newcomer. Here was a man who must, judging by his agitation, have been pretty closely connected with Francis Coburn. Suspicious of everyone, the detective recognized that there might be more here than met the eye. He drew out his notebook.

“I am glad you called, sir,” he said pleasantly. “We shall be very pleased to get any information you can give us. What was your friend like?”

His quiet, conversational manner calmed the other.

“Rather tall,” he answered anxiously, “with a long pale face, and small, black, pointed mustache.”

“I'm afraid, sir, that's the man. I think if you don't mind you had better see if you can identify him.”

“I want to,” Merriman cried, leaping to his feet “I must know at once.”

Willis rose also.

“Then come this way.”

They drove quickly across town. A glance was sufficient to tell Merriman that the body was indeed that of his former acquaintance. His agitation became painful.

“You're right!” he cried. “It is he! And it's my fault. Oh, if I had only done what she said! If I had only kept out of it!”

He wrung his hands in his anguish.

Willis was much interested. Though this man could not be personally guilty—he was not tall enough, for one thing—he must surely know enough about the affair to put the inspector on the right track. The latter began eagerly to await his story.

Merriman for his part was anxious for nothing so much as to tell it. He was sick to death of plots and investigations and machinations, and while driving to the Yard he had made up his mind that if the dead man were indeed Madeleine's father, he would tell the whole story of his and Hilliard's investigations into the doings of the syndicate. When, therefore, they were back in the inspector's room, he made a determined effort to pull himself together and speak calmly.

“Yes,” he said, “I know him. He lived near Bordeaux with his daughter. She will be absolutely alone. You will understand that I must go out to her by the first train, but until then I am at your service.

“You are a relation perhaps?”

“No, only an acquaintance, but—I'm going to tell you the whole story, and I may as well say, once for all, that it is my earnest hope some day to marry Miss Coburn.”

Willis bowed and inquired, “Is Miss Coburn's name Madeleine?”

“Yes,” Merriman answered, surprise and eagerness growing in his face.

“Then,” Willis went on, “you will be pleased to learn that she is not in France—at least, I think not. She left the Peveril Hotel in Russell Square about eleven o'clock yesterday morning.”

Merriman sprang to his feet.

“In London?” he queried excitedly. “Where? What address?”

“We don't know yet, but we shall soon find her. Now, sir, you can't do anything for the moment, and I am anxious to hear your story. Take your own time, and the more details you can give me the better.”

Merriman controlled himself with an effort.

“Well,” he said slowly, sitting down again, “I have something to tell you, inspector. My friend Hilliard—Claud Hilliard of the Customs Department—and I have made a discovery. We have accidentally come on what we believe is a criminal conspiracy, we don't know for what purpose, except that it is something big and fraudulent. We were coming to the Yard in any case to tell what we had learned, but this murder has precipitated things. We can no longer delay giving our information. The only thing is that I should have liked Hilliard to be here to tell it instead of me, for our discovery is really due to him.”

“I can see Mr. Hilliard afterwards. Meantime tell me the story yourself.”

Merriman thereupon related his and Hilliard's adventures and experiences from his own first accidental visit to the clearing when he noticed the changing of the lorry number, right up to his last meeting with Mr. Coburn, when the latter expressed his intention of breaking away from the gang. He hid nothing, explaining without hesitation his reasons for urging the delay in informing the authorities, even though he quite realized his action made him to some extent an accomplice in the conspiracy.

Willis was much more impressed by the story than he would have admitted. Though it sounded wild and unlikely, then was a ring of truth in Merriman's manner which went far to convince the other of its accuracy. He did not believe either that anyone could have invented such a story. It's very improbability was an argument for its truth.

And if it were true, what a vista it opened up to himself! The solution of the murder problem would be gratifying enough but it was a mere nothing compared to the other. If he could search out and bring to naught such a conspiracy as Merriman's story indicated, he would be a made man. It would be the crowning point of his career, and would bring him measurably nearer to that cottage and garden in the country to which for years past he had been looking forward. Therefore no care and trouble would be too great to spend on the matter.

Putting away thoughts of self, therefore, and deliberately concentrating on the matter in hand, he set himself to consider in detail what his visitor had told him and get the story clear in his mind. Then slowly and painstakingly he began to ask questions.

“I take it, Mr. Merriman, that your idea is that Mr. Coburn was murdered by a member of the syndicate?”

“Yes, and I think he foresaw his fate. I think when he told them he was going to break with them they feared he might betray them, and wanted to be on the safe side.”

“Any of them a tall, stoutly built man?”

“Captain Beamish is tall and strongly built, but I should not say he was stout.”

“Describe him.”

“He stooped and was a little round-shouldered, but even then he was tall. If he had held himself up he would have been a big man. He had a heavy face with a big jaw, thin lips, and a vindictive expression.”

Willis, though not given to jumping to conclusions, felt suddenly thrilled, and he made up his mind that an early development in the case would be the taking of the impressions of Captain Beamish's right thumb and forefinger.

He asked several more questions and, going over the story again, took copious notes. Then for some time he sat in silence considering what he had heard.

At first sight he was inclined to agree with Merriman, that the deceased had met his death at the hands of a member of the syndicate, and if so, it was not unlikely that all or most of the members were party to it. From the mere possibility of this it followed that the most urgent thing for the moment was to prevent the syndicate suspecting his knowledge. He turned again to his visitor.

“I suppose you realize, Mr. Merriman, that if all these details you have given me are correct, you yourself are in a position of some danger?”

“I know it, but I am not afraid. It is the possible danger to Miss Coburn that has upset me so much.”

“I understand, sir,” the inspector returned sympathetically, “but it follows that for both your sakes you must act very cautiously, so as to disarm any suspicions these people may have of you.”

“I am quite in your hands, inspector.”

“Good. Then let us consider your course of action. Now, first of all about the inquest. It will be held this evening at five o'clock. You will have to give evidence, and we shall have to settle very carefully what that evidence will be. No breath of suspicion against the syndicate must leak out.”

Merriman nodded.

“You must identify the deceased, and, if asked, you must tell the story of your two visits to the clearing. You must speak without the slightest hesitation. But you must of course make no mention of the changing of the lorry numbers or of your suspicions, nor will you mention your visit to Hull. You will explain that you went back to the clearing on the second occasion because it was so little out of your way and because you were anxious to meet the Coburns again, while your friend wanted to see the forests of Les Landes.”

Merriman again nodded.

“Then both you and your friend must avoid Scotland Yard. It is quite natural that you should rush off here as you did, but it would not be natural for you to return. And there is no reason why Mr. Hilliard should come at all. If I want to see either of you I shall ring up and arrange a place of meeting. And just two other things. The first is that I need hardly warn you to be as circumspect in your conversation as in your evidence. Keep in mind that each stranger that you may meet may be Morton or some other member of the gang. The second is that I should like to keep in touch with you for the remainder of the day in case any question might crop up before the inquest. Where will you be?”

“I shall stay in my club, Rover's, in Cranbourne Street. You can ring me up.”

“Good,” Willis answered, rising to his feet. “Then let me say again how pleased I am to have met you and heard your story. Five o'clock, then, if you don't hear to the contrary.”

When Merriman had taken his leave the inspector sat on at his desk, lost in thought. This case bade fair to be the biggest he had ever handled, and he was anxious to lay his plans so as to employ his time to the best advantage. Two clearly defined lines of inquiry had already opened out, and he was not clear which to follow. In the first place, there was the obvious routine investigation suggested directly by the murder. That comprised the finding of Miss Coburn, the learning of Mr. Coburn's life history, the tracing of his movements during the last four or five days, the finding of the purchaser of the black cloth, and the following up of clues discovered during these inquiries. The second line was that connected with the activities of the syndicate, and Willis was inclined to believe that a complete understanding of these would automatically solve the problem of the murder. He was wondering whether he should not start an assistant on the routine business of the tragedy, while himself concentrating on the pit-prop business, when his cogitations were brought to an end by a messenger. A lady had called in connection with the case.

“Miss Madeleine Coburn,” thought Willis, as he gave orders for her to be shown to his room, and when she entered he instantly recognized the original of the photograph.

Madeleine's face was dead white and there was a strained look of horror in her eyes, but she was perfectly calm and sell-possessed.

“Miss Coburn?” Willis said, as he rose and bowed. “I am afraid I can guess why you have called. You saw the account in the paper?”

“Yes.” She hesitated. “Is it—my father?”

Willis told her as gently as he could. She sat quite still for a few moments, while he busied himself with some papers, then she asked to see the body. When they had returned to Willis's room he invited her to sit down again.

“I very deeply regret, Miss Coburn,” he said, “to have to trouble you at this time with questions, but I fear you will have to give evidence at the inquest this afternoon, and it will be easier for yourself to make a statement now, so that only what is absolutely necessary need be asked you then.”

Madeleine seemed stunned by the tragedy, and she spoke as if in a dream.

“I am ready to do what is necessary.”

He thanked her, and began by inquiring about her father's history. Mr. Coburn, it appeared, had had a public school and college training, but, his father dying when he was just twenty, and leaving the family in somewhat poor circumstances, he had gone into business as a clerk in the Hopwood Manufacturing Company, a large engineering works in the Midlands. In this, he had risen until he held the important position of cashier, and he and his wife and daughter had lived in happiness and comfort during the latter's girlhood. But some six years previous to the tragedy which had just taken place a change had come over the household. In the first place, Mrs. Coburn had developed a painful illness and had dragged out a miserable existence for the three years before her death. At the same time, whether from the expense of the illness or from other causes Miss Coburn did not know, financial embarrassment seemed to descend on her father. One by one their small luxuries were cut off, then their house had to be given up, and they had moved to rooms in a rather poor locality of the town. Their crowning misfortune followed rapidly. Mr. Coburn gave up his position at the works, and for a time actual want stared them in the face. Then this Pit-Prop Syndicate had been formed, and Mr. Coburn had gone into it as the manager of the loading station. Miss Coburn did not know the reason of his leaving the engineering works, but she suspected there had been friction, as his disposition for a time had changed, and he had lost his bright manner and vivacity. He had, however, to a large extent recovered while in France. She was not aware, either, of the terms on which he had entered the syndicate, but she imagined he shared in the profits instead of receiving a salary.

These facts, which Willis obtained by astute questioning, seemed to him not a little suggestive. From what Mr. Coburn had himself told Merriman, it looked as if there had been some secret in his life which had placed him in the power of the syndicate, and the inspector wondered whether this might not be connected with his leaving the engineering works. At all events inquiries there seemed to suggest a new line of attack, should such become necessary.

Willis then turned to the events of the past few days. It appeared that about a fortnight earlier, Mr. Coburn announced that he was crossing to London for the annual meeting of the syndicate, and, as he did not wish his daughter to be alone at the clearing, it was arranged that she should accompany him. They travelled by the Girondin to Hull, and coming on to London, put up at the Peveril. Mr. Coburn had been occupied off and on during the four days they had remained there, but the evenings they had spent together in amusements. On the night of the murder, Mr. Coburn was to have left for Hull to return to France by the Girondin, his daughter going by an earlier train to Eastbourne, where she was to have spent ten days with an aunt. Except for what Mr. Coburn had said about the meeting of the syndicate, Madeleine did not know anything of his business in town, nor had she seen any member of the syndicate after leaving the ship.

Having taken notes of her statements, Willis spoke of the inquest and repeated the instructions he had given Merriman as to the evidence. Then he told her of the young man's visit, and referring to his anxiety on her behalf, asked if he might acquaint him with her whereabouts. She thankfully acquiesced, and Willis, who was anxious that her mind should be kept occupied until the inquest, pushed his good offices to the extent of arranging a meeting between the two.

The inquest elicited no further information. Formal evidence of identification was given, the doctors deposed that death was due to a bullet from an exceedingly small bore automatic pistol, the cab driver and porter told their stories, and the jury returned the obvious verdict of murder against some person or persons unknown. The inspector's precautions were observed, and not a word was uttered which could have given a hint to any member of the Pit-Prop Syndicate that the bona fides of his organization was suspected.

Two days later, when the funeral was over, Merriman took Miss Coburn back to her aunt's at Eastbourne. No word of love passed his lips, but the young girl seemed pleased to have his company, and before parting from her he obtained permission to call on her again. He met the aunt for a few moments, and was somewhat comforted to find her a kind, motherly woman, who was evidently sincerely attached to the now fatherless girl. He had told Madeleine of his interview with her father, and she had not blamed him for his part in the matter, saying that she had believed for some time that a development of the kind was inevitable.

So, for them, the days began to creep wearily past. Merriman paid as frequent visits to Eastbourne as he dared, and little by little he began to hope that he was making progress in his suit. But try as he would, he could not bring the matter to a head. The girl had evidently had a more severe shock than they had realized at first, and she became listless and difficult to interest in passing events. He saw there was nothing for it but to wait, and he set himself to bide his time with the best patience he could muster.