eye? Could he have had any special reason for knocking at this particular gate? And what on earth could he be doing with that walking-stick gun?
Reflections such as these pervaded Mr. Pottermack’s consciousness as he went about his various occupations. They did not seriously disturb his peace of mind, but still they did create a certain degree of unrest, and this presently revived in his mind certain plans which he had considered and rejected; plans for further establishing his security by shifting the field of possible inquiry yet farther from his own neighbourhood.
On Thorndyke the effects of the meeting were quite different. He had come doubting if a certain surmise that he had formed could possibly be correct. He had gone away with his doubts dispelled and his surmise converted into definite belief. The only unsolved question that remained in his mind was, “Who was Marcus Pottermack?” The answer that suggested itself was improbable in the extreme. But it was the only one that he could produce, and if it were wrong he was at the end of his unassisted resources.
The first necessity, therefore, was to eliminate the improbable—or else to confirm it. Then he would know where he stood and could consider what action he would take. Accordingly he began by working up the scanty material that he had collected. The photographs, when developed and enlarged by Polton, yielded two very fair portraits of Mr. Pottermack showing clearly the right and left profiles respectively; and while Polton was dealing with these, his principal made a systematic, but not very hopeful, inspection of the map in search of possible fingerprints. He had made a mental note of the way in which Pottermack had held the map, and even of the spots which his fingertips had touched, and on these he now began cautiously to operate with two fine powders, a black and a white, applying each to its appropriate background.
The results were poor enough, but yet they were better than he had expected. Pottermack had held the map in his left hand, the better to manipulate the pencil with which he pointed, and his thumb had been planted on a green patch which represented a wood. Here the white powder settled and showed a print which, poor as it was, would present no difficulties to the experts and which would be more distinct in a photograph, as the background would then appear darker. The prints of the fingertips which the black powder brought out on the white background were more imperfect and were further confused by the black lettering. Still, Thorndyke had them all carefully photographed and enlarged to twice the natural size, and, having blocked out on the negative the surrounding lettering (to avoid giving any information that might be better withheld), had prints made and mounted on card.
With these in his letter-case and the two portraits in his pocket, he set forth one morning for New Scotland Yard, proposing to seek the assistance of his old friend, Mr. Superintendent Miller, or, if he should not be available, that of the officer in charge of criminal records. However, it happened fortunately that the Superintendent was in his office, and thither Thorndyke, having sent in his card, was presently conducted.
“Well, doctor,” said Miller, shaking hands heartily, “here you are, gravelled as usual. Now what sort of mess do you want us to help you out of?”
Thorndyke produced his letter-case, and, extracting the photographs, handed them to the Superintendent.
“Here,” he said, “are three fingerprints; apparently the thumb and first two fingers of the left hand.”
“Ha,” said Miller, inspecting the three photographs critically. “Why ‘apparently’?”
“I mean,” explained Thorndyke, “that that was what I inferred from their position on the original document.”
“Which seems to have been a map,” remarked Miller, with a faint grin. “Well, I expect you know. Shall I take it that they are the thumb and index and middle finger of the left hand?”
“I think you may,” said Thorndyke.
“I think I may,” agreed Miller; “and now the question is: What about it? I suppose you want us to tell you whose fingerprints they are; and you want to gammon us that you don’t know already. And I suppose—as I see you have been faking the negative—that you don’t want to give us any information?”
“In effect,” replied Thorndyke, “you have, with your usual acuteness, diagnosed the position exactly. I don’t much want to give any details, but I will tell you this much. If my suspicions are correct, these are the fingerprints of a man who has been dead some years.”
“Dead!” exclaimed Miller. “Good Lord, doctor, what a vindictive man you are! But you don’t suppose that we follow the criminal class into the next world, do you?”
“I have been assuming that you don’t destroy records. If you do, you are unlike any government officials that I have ever met. But I hope I was right.”
“In the main, you were. We don’t keep the whole set of documents of a dead man, but we have a set of skeleton files on which the personal documents—the fingerprints, photographs and description—are preserved. So I expect we shall be able to tell you what you want to know.”
“I am sorry,” said Thorndyke, “that they are such wretchedly poor prints. You don’t think that they are too imperfect to identify, I hope.”
Miller inspected the photographs afresh. “I don’t see much amiss with them,” said he. “You can’t expect a crook to go about with a roller and inking-plate in his pocket so as to give you nice sharp prints. These are better than a good many that our people have to work from. And besides, there are three digits from one hand. That gives you part of the formula straight away. No, the experts won’t make any trouble about these. But supposing these prints are not on the file?”
“Then we shall take it that I suspected the wrong man.”
“Quite so. But, if I am not mistaken, your concern is to prove whose fingerprints they are in order that you can say whose fingerprints they are not. Now, supposing that we don’t find them on the files of the dead men, would it help you if we tried the current files—the records of the crooks who are still in business? Or would you rather not?”
“If it would not be giving you too much trouble,” said Thorndyke, “I should be very much obliged if you would.”
“No trouble at all,” said Miller, adding with a sly smile: “only it occurred to me that it might be embarrassing to you if we found your respected client’s fingerprints on the live register.”
“That would be a highly interesting development,” said Thorndyke, “though I don’t think it a likely one. But it is just as well to exhaust the possibilities.”
“Quite,” agreed Miller; and thereupon he wrote the brief particulars on a slip of paper which he put into an envelope with the photographs, and, having rung a bell, handed the envelope to the messenger who appeared in response to the summons.
“I don’t suppose we shall have to keep you waiting very long,” said the Superintendent. “They have an extraordinarily ingenious system of filing. Out of all the thousands of fingerprints that they have, they can pounce on the one that is wanted in the course of a few minutes. It seems incredible, and yet it is essentially simple—just a matter of classification and ringing the changes on different combinations of types.”
“You are speaking of completely legible prints?” suggested Thorndyke.
“Yes, the sort of prints that we get sent in from local prisons for identification of a man who has been arrested under a false name. Of course, when we get a single imperfect print found by the police at a place where a crime has been committed, a bit more
