"No machine can lie," said Father Brown; "nor can it tell the truth."

"It did in this case, as I'll show you," went on Usher positively.

"I sat the man in the ill-fitting clothes in a comfortable chair, and simply wrote words on a blackboard; and the machine simply recorded the variations of his pulse; and I simply observed his manner. The trick is to introduce some word connected with the supposed crime in a list of words connected with something quite different, yet a list in which it occurs quite naturally. Thus I wrote 'heron' and 'eagle' and 'owl', and when I wrote 'falcon' he was tremendously agitated; and when I began to make an 'r' at the end of the word, that machine just bounded. Who else in this republic has any reason to jump at the name of a newly-arrived Englishman like Falconroy except the man who's shot him? Isn't that better evidence than a lot of gabble from witnesses--if the evidence of a reliable machine?"

"You always forget," observed his companion, "that the reliable machine always has to be worked by an unreliable machine."

"Why, what do you mean?" asked the detective.

"I mean Man," said Father Brown, "the most unreliable machine I know of.

I don't want to be rude; and I don't think you will consider Man to be an offensive or inaccurate description of yourself. You say you observed his manner; but how do you know you observed it right? You say the words have to come in a natural way; but how do you know that you did it naturally? How do you know, if you come to that, that he did not observe your manner? Who is to prove that you were not tremendously agitated?

There was no machine tied on to your pulse."

"I tell you," cried the American in the utmost excitement, "I was as cool as a cuc.u.mber."

"Criminals also can be as cool as cuc.u.mbers," said Brown with a smile.

"And almost as cool as you."

"Well, this one wasn't," said Usher, throwing the papers about. "Oh, you make me tired!"

"I'm sorry," said the other. "I only point out what seems a reasonable possibility. If you could tell by his manner when the word that might hang him had come, why shouldn't he tell from your manner that the word that might hang him was coming? I should ask for more than words myself before I hanged anybody."

Usher smote the table and rose in a sort of angry triumph.

"And that," he cried, "is just what I'm going to give you. I tried the machine first just in order to test the thing in other ways afterwards and the machine, sir, is right."

He paused a moment and resumed with less excitement. "I rather want to insist, if it comes to that, that so far I had very little to go on except the scientific experiment. There was really nothing against the man at all. His clothes were ill-fitting, as I've said, but they were rather better, if anything, than those of the submerged cla.s.s to which he evidently belonged. Moreover, under all the stains of his plunging through ploughed fields or bursting through dusty hedges, the man was comparatively clean. This might mean, of course, that he had only just broken prison; but it reminded me more of the desperate decency of the comparatively respectable poor. His demeanour was, I am bound to confess, quite in accordance with theirs. He was silent and dignified as they are; he seemed to have a big, but buried, grievance, as they do.

He professed total ignorance of the crime and the whole question; and showed nothing but a sullen impatience for something sensible that might come to take him out of his meaningless sc.r.a.pe. He asked me more than once if he could telephone for a lawyer who had helped him a long time ago in a trade dispute, and in every sense acted as you would expect an innocent man to act. There was nothing against him in the world except that little finger on the dial that pointed to the change of his pulse.

"Then, sir, the machine was on its trial; and the machine was right.

By the time I came with him out of the private room into the vestibule where all sorts of other people were awaiting examination, I think he had already more or less made up his mind to clear things up by something like a confession. He turned to me and began to say in a low voice: 'Oh, I can't stick this any more. If you must know all about me--'

"At the same instant one of the poor women sitting on the long bench stood up, screaming aloud and pointing at him with her finger. I have never in my life heard anything more demoniacally distinct. Her lean finger seemed to pick him out as if it were a pea-shooter. Though the word was a mere howl, every syllable was as clear as a separate stroke on the clock.

"'Drugger Davis!' she shouted. 'They've got Drugger Davis!'

"Among the wretched women, mostly thieves and streetwalkers, twenty faces were turned, gaping with glee and hate. If I had never heard the words, I should have known by the very shock upon his features that the so-called Oscar Rian had heard his real name. But I'm not quite so ignorant, you may be surprised to hear. Drugger Davis was one of the most terrible and depraved criminals that ever baffled our police. It is certain he had done murder more than once long before his last exploit with the warder. But he was never entirely fixed for it, curiously enough because he did it in the same manner as those milder--or meaner--crimes for which he was fixed pretty often. He was a handsome, well-bred-looking brute, as he still is, to some extent; and he used mostly to go about with barmaids or shop-girls and do them out of their money. Very often, though, he went a good deal farther; and they were found drugged with cigarettes or chocolates and their whole property missing. Then came one case where the girl was found dead; but deliberation could not quite be proved, and, what was more practical still, the criminal could not be found. I heard a rumour of his having reappeared somewhere in the opposite character this time, lending money instead of borrowing it; but still to such poor widows as he might personally fascinate, but still with the same bad result for them. Well, there is your innocent man, and there is his innocent record. Even, since then, four criminals and three warders have identified him and confirmed the story. Now what have you got to say to my poor little machine after that? Hasn't the machine done for him? Or do you prefer to say that the woman and I have done for him?"

"As to what you've done for him," replied Father Brown, rising and shaking himself in a floppy way, "you've saved him from the electrical chair. I don't think they can kill Drugger Davis on that old vague story of the poison; and as for the convict who killed the warder, I suppose it's obvious that you haven't got him. Mr Davis is innocent of that crime, at any rate."

"What do you mean?" demanded the other. "Why should he be innocent of that crime?"

"Why, bless us all!" cried the small man in one of his rare moments of animation, "why, because he's guilty of the other crimes! I don't know what you people are made of. You seem to think that all sins are kept together in a bag. You talk as if a miser on Monday were always a spendthrift on Tuesday. You tell me this man you have here spent weeks and months wheedling needy women out of small sums of money; that he used a drug at the best, and a poison at the worst; that he turned up afterwards as the lowest kind of moneylender, and cheated most poor people in the same patient and pacific style. Let it be granted--let us admit, for the sake of argument, that he did all this. If that is so, I will tell you what he didn't do. He didn't storm a spiked wall against a man with a loaded gun. He didn't write on the wall with his own hand, to say he had done it. He didn't stop to state that his justification was self-defence. He didn't explain that he had no quarrel with the poor warder. He didn't name the house of the rich man to which he was going with the gun. He didn't write his own, initials in a man's blood. Saints alive! Can't you see the whole character is different, in good and evil?

Why, you don't seem to be like I am a bit. One would think you'd never had any vices of your own."

The amazed American had already parted his lips in protest when the door of his private and official room was hammered and rattled in an unceremonious way to which he was totally unaccustomed.

The door flew open. The moment before Greywood Usher had been coming to the conclusion that Father Brown might possibly be mad. The moment after he began to think he was mad himself. There burst and fell into his private room a man in the filthiest rags, with a greasy squash hat still askew on his head, and a shabby green shade shoved up from one of his eyes, both of which were glaring like a tiger's. The rest of his face was almost undiscoverable, being masked with a matted beard and whiskers through which the nose could barely thrust itself, and further buried in a squalid red scarf or handkerchief. Mr Usher prided himself on having seen most of the roughest specimens in the State, but he thought he had never seen such a baboon dressed as a scarecrow as this. But, above all, he had never in all his placid scientific existence heard a man like that speak to him first.

"See here, old man Usher," shouted the being in the red handkerchief, "I'm getting tired. Don't you try any of your hide-and-seek on me; I don't get fooled any. Leave go of my guests, and I'll let up on the fancy clockwork. Keep him here for a split instant and you'll feel pretty mean. I reckon I'm not a man with no pull."

The eminent Usher was regarding the bellowing monster with an amazement which had dried up all other sentiments. The mere shock to his eyes had rendered his ears, almost useless. At last he rang a bell with a hand of violence. While the bell was still strong and pealing, the voice of Father Brown fell soft but distinct.

"I have a suggestion to make," he said, "but it seems a little confusing. I don't know this gentleman--but--but I think I know him. Now, you know him--you know him quite well--but you don't know him--naturally. Sounds paradoxical, I know."

"I reckon the Cosmos is cracked," said Usher, and fell asprawl in his round office chair.

"Now, see here," vociferated the stranger, striking the table, but speaking in a voice that was all the more mysterious because it was comparatively mild and rational though still resounding. "I won't let you in. I want--"

"Who in h.e.l.l are you?" yelled Usher, suddenly sitting up straight.

"I think the gentleman's name is Todd," said the priest.

Then he picked up the pink slip of newspaper.

"I fear you don't read the Society papers properly," he said, and began to read out in a monotonous voice, "'Or locked in the jewelled bosoms of our city's gayest leaders; but there is talk of a pretty parody of the manners and customs of the other end of Society's scale.' There's been a big Slum Dinner up at Pilgrim's Pond tonight; and a man, one of the guests, disappeared. Mr Ireton Todd is a good host, and has tracked him here, without even waiting to take off his fancy-dress."

"What man do you mean?"

"I mean the man with comically ill-fitting clothes you saw running across the ploughed field. Hadn't you better go and investigate him? He will be rather impatient to get back to his champagne, from which he ran away in such a hurry, when the convict with the gun hove in sight."

"Do you seriously mean--" began the official.

"Why, look here, Mr Usher," said Father Brown quietly, "you said the machine couldn't make a mistake; and in one sense it didn't. But the other machine did; the machine that worked it. You a.s.sumed that the man in rags jumped at the name of Lord Falconroy, because he was Lord Falconroy's murderer. He jumped at the name of Lord Falconroy because he is Lord Falconroy."

"Then why the blazes didn't he say so?" demanded the staring Usher.

"He felt his plight and recent panic were hardly patrician," replied the priest, "so he tried to keep the name back at first. But he was just going to tell it you, when"--and Father Brown looked down at his boots--"when a woman found another name for him."

"But you can't be so mad as to say," said Greywood Usher, very white, "that Lord Falconroy was Drugger Davis."

The priest looked at him very earnestly, but with a baffling and undecipherable face.

"I am not saying anything about it," he said. "I leave all the rest to you. Your pink paper says that the t.i.tle was recently revived for him; but those papers are very unreliable. It says he was in the States in youth; but the whole story seems very strange. Davis and Falconroy are both pretty considerable cowards, but so are lots of other men. I would not hang a dog on my own opinion about this. But I think," he went on softly and reflectively, "I think you Americans are too modest. I think you idealize the English aristocracy--even in a.s.suming it to be so aristocratic. You see a good-looking Englishman in evening-dress; you know he's in the House of Lords; and you fancy he has a father. You don't allow for our national buoyancy and uplift. Many of our most influential n.o.blemen have not only risen recently, but--"

"Oh, stop it!" cried Greywood Usher, wringing one lean hand in impatience against a shade of irony in the other's face.

"Don't stay talking to this lunatic!" cried Todd brutally. "Take me to my friend."

Next morning Father Brown appeared with the same demure expression, carrying yet another piece of pink newspaper.

"I'm afraid you neglect the fashionable press rather," he said, "but this cutting may interest you."

Usher read the headlines, "Last-Trick's Strayed Revellers: Mirthful Incident near Pilgrim's Pond." The paragraph went on: "A laughable occurrence took place outside Wilkinson's Motor Garage last night.

A policeman on duty had his attention drawn by larrikins to a man in prison dress who was stepping with considerable coolness into the steering-seat of a pretty high-toned Panhard; he was accompanied by a girl wrapped in a ragged shawl. On the police interfering, the young woman threw back the shawl, and all recognized Millionaire Todd's daughter, who had just come from the Slum Freak Dinner at the Pond, where all the choicest guests were in a similar deshabille. She and the gentleman who had donned prison uniform were going for the customary joy-ride."

Under the pink slip Mr Usher found a strip of a later paper, headed, "Astounding Escape of Millionaire's Daughter with Convict. She had Arranged Freak Dinner. Now Safe in--"

Mr Greenwood Usher lifted his eyes, but Father Brown was gone.