They were hanging intently on every word.
“Well,” drawled Ellery, “let’s re-examine the crumpled half found on the floor of Dr. Xavier’s study. Let’s smooth it out, turn it around so that the thumb print is at the top. Why at the top? Because everyone tears from the top down, not from the bottom up. That’s why I said the second method doesn’t substantially differ in effect from the first. The thumbprint, despite the difference in angle, is still relatively in the same corner of the card, and it’s the thumbprint of the same hand. Now, holding the smoothed piece in the position it must have taken when the card was torn, what do we see?” He puffed again. “That the torn edge of the card is on the right, that the thumbprint is pointing diagonally upwards toward the upper right-hand corner or, to express it in other words, that it was the left thumb which left its smudge there, and consequently the left hand which held that torn and crumpled half of the card!”
“You mean,” whispered Miss Forrest, “that a left-handed person—”
“You’re sharp, Miss Forrest,” smiled Ellery. “That’s exactly what I do mean. The murderer’s left hand had held that half. The murderer, then had crumpled that half in his left hand and thrown it away with his left hand. The left hand, then, did all the work. Ergo, as you say, the murderer of Dr. Xavier and the framer of Mrs. Xavier was left-handed.” He paused briefly to study their puzzled faces. “The problem resolved itself, therefore, into discovering which of you ladies and gentlemen, if any, was left-handed.” The puzzlement vanished, to be replaced by alarm. “That was the purpose of our slightly grotesque tests tonight.”
“A trick,” said Dr. Holmes indignantly.
“But an extremely essential one, Doctor. As a matter of fact, it wasn’t so much a test to acquire knowledge as a little research into the psychology of guilt. I knew before we conducted the tests who was right-handed and who was not, purely from recollected observations. I knew, too, from the same source that none of you is ambidextrous. Now there were three people whom we’ve neglected to test tonight: Mrs. Xavier and the Carreau boys.” The twins started. “But Mrs. Xavier, aside from the fact that she was framed and would scarcely have framed herself, is also right-handed, as I’ve had occasion to note many times. As for the twins, preposterous as even the theoretical notion of their guilt is, Francis on the right is naturally right-handed, as I’ve also observed; and Julian on the left, who is left-handed, has his left arm broken and in a cast, making digital manipulation impossible. And,” he added dryly, “since I’m thorough in all things, I’ve proved to my own satisfaction that the only way the lads could have achieved the effect of those thumbprints under the circumstances would have been by crossing their adjoining hands and tearing — a procedure so pointless that it need not be considered... Well, now!” His eyes glittered. “Who among the rest of you is left-handed? Do you recall what you did tonight, all of you?”
They stirred uneasily biting their lips, frowning.
“Ill tell you what you did,” continued Ellery softly. “Miss Forrest, you picked up the revolver and attempted to discharge it with you right hand. Mr. Smith, you held the revolver in your left hand. But polished it clean with your right. Dr. Holmes, you conducted your mock-examination of my theoretically dead body, I am happy to report, with your right hand almost exclusively. Mrs. Wheary, you snapped the switch with your right hand, and you, Bones, struck a match with your right hand. Mrs. Carreau held the deck of cards in her left hand and dealt with the right—”
“Hold up,” grunted the Inspector, coming forward again. “We’ve got just what we want now. I might explain that Mr. Queen conducted these experiments for my benefit, to prove who was right-handed and who wasn’t. I hadn’t noticed before.” He produced a pencil and paper from one of his pockets and suddenly slapped them down upon the bridge table before the astonished lawyer. “Here, Xavier, I want you to act as our recording secretary. This is a little memorandum to the Sheriff of Osquewa, Winslowe Reid — if and when he gets here.” He continued irritably without pausing: “Come, come, man, don’t sit there dreaming. Write, will you?”
It was all so neat and smooth and noiselessly efficient. The whole psychological effect had been calculated to the last nice detail The irritability of the Inspector, impersonally directed at his head, caused Xavier to snatch up the pencil, his lips working, and poise it above the sheet.
“Write this now,” growled the Inspector, pacing up and down. “ ‘My brother, Dr. John S. Xavier—’ ” the lawyer wrote quickly, with brutal jabs of the pencil, his face pale as death — “ ‘murdered in his study on the ground floor of Arrow Head, his residence situated on Arrow Mountain in Tuckesas County, fifteen miles from the nearest seat of jurisdiction, Osquewa, met his death by shooting at the hand of—’ ” the Inspector paused, and the pencil in Mark Xavier’s left hand trembled, “ ‘at the hand of myself!’ Now sign your name, damn you!”
For a suspended moment, an interval without duration, there was utter silence. They sat forward in their chairs bleakly, without movement, struck dumb.
The pencil dropped from Xavier’s fingers and his shoulders humped with an instinctive defensive contraction of his muscles. His bloodshot eyes were glassy. Then before any of them could stir he was out of the chair, a coordinated organism of terrified nerves and unmanned flesh. The table turned over as he leaped. He bounced the few steps to the French window nearest the table and crashed out upon the terrace.
The Inspector woke up. “Stop!” he shouted. “Stop, I tell you! Or I’ll stop you with a bullet!”
But Xavier did not stop. He scrambled over the terrace rail, landing with a crunching thud on the gravel below. His figure began to fade out as he receded farther from the light shining from the game-room.
They rose in unison, without moving from their places, and craned out into the darkness, mesmerized. Ellery stood very still, cigarette checked an inch before his lips.
The Inspector uttered a curious sigh, reached into his hip pocket, drew out his service revolver, snapped the safety catch off, leaned against the side of one of the tall windows, aimed at the ghostly dodging figure, and deliberately fired.