He stopped and for a moment there was only the terrifying crackle above their heads. Occasionally in the past few moments there had been a dull thud on the floor above. Now there was another... But they scarcely heard. They were in the grip again of fascinated interest.
“But what—” began Miss Forrest, rocking to and fro.
“Don’t you see it yet?” said Ellery almost cheerfully. “Dr. Xavier was right-handed. I’ve proved long ago that a right-handed man tearing a card in two would tear with his right, crumple with his right — or if he didn’t crumple, at least throw the discarded half away with his right, since it made no difference which half he retained and which he threw away, both halves being exactly the same. This would leave the automatically retained half in his left. But I’ve demonstrated that the retained half must have been in Dr. Xavier’s right when Mark found him. Therefore Dr. Xavier had never torn that card at all. Therefore someone else had torn that jack and left it in his right hand. Therefore that half-jack, meant to incriminate the twins, was also a frame-up, and the twins must be held entirely innocent of the murder of Dr. Xavier.”
They were too stupefied to smile or show relief or do anything but gape at him. It did seem a small matter, Ellery thought, with death lurking for them all, innocent and guilty, beyond the closed door above.
“Since the first frame-up,” he went on quickly, “was arranged before two-thirty, before Mark blundered upon the scene of the crime, I think we have a perfect right to assert that the first frame-up of the Carreau boys by means of the jack of diamonds had been arranged by the murderer. Unless we go into the far-fetched theory that that framer wasn’t the murderer either, that that framer came before Mark but followed the murderer; in other words, that there were two framers besides the murderer.” He shook his head. “Much too fantastic. The framer of the twins was the murderer.”
“This business about the rigor proving that it was the murderer and not Dr. Xavier who left the jack of diamonds accusing the twins,” said the Inspector dubiously, interested despite himself, “sounds a — well, a little arbitrary to me. It doesn’t sound very convincing.”
“That?” Ellery smiled in his desperate effort to take their minds off the flames. “Oh, I assure you it’s fact, not theory. I can confirm it. But before I do that I want to point out that logically another question then arose: was the murderer of Mark Xavier the same as the murderer of his brother? Despite the overwhelming probability that the same individual committed both crimes, we had no logical right to assume it. I didn’t assume it. I proved it to my own satisfaction.
“For what was the state of affairs just before Mark’s murder? The man had lapsed into unconsciousness just before he could reveal what he claimed was the name of his brother’s murderer. Dr. Holmes asserted that there was every chance the wounded man would recover consciousness in a few hours. Everyone was present to hear that assertion. Who therefore was in the greatest danger should Mark recover consciousness? Obviously, if we are to recognize the most elementary truth about cause and effect, the person who thought he was going to be unmasked by the dying man; that is, the person with the guilty conscience, Dr. Xavier’s murderer. Consequently I say that, under these special and weighty circumstances, it would be flying in the face of reason to doubt that it was John Xavier’s murderer who crept into Mark’s bedroom the other night and poisoned him to keep him forever silent. And, mind you, this is true whether Mark really knew who the murderer was or not! The mere threat was sufficient to force the murderer’s hand.”
“No quarrel with that,” muttered the Inspector.
“Actually, we have confirmation of this. Let’s suppose the alternative: that there were two murderers, that the killer of Mark was a different person from the killer of John. Would such a second killer have chosen the worst possible time to commit his crime? — worst possible, I say, since he knew that Mark was under guard by a professional detective, and armed to boot? No, the only person who would have risked this danger was someone who had to risk it; who had to kill Mark not any time, but that very night, before Mark could come back to his senses and speak up. So I say, and I don’t think there can be any logical or psychological weakness in the argument, that we are dealing with only one criminal.”
“Nobody’s questioned that. But how can you confirm your conclusion that it was the murderer, not Dr. Xavier, who left the jack of diamonds accusing the boys?”
“I was coming to that. I don’t have to confirm it, really. We’ve the murderer’s own confession that he framed the twins after killing Dr. Xavier.”
“Confession?” They all gaped with the Inspector at that.
“Of action rather than speech. I daresay most of these good folk would be astonished to learn that after Mark Xavier’s death someone tampered with the lock of the cabinet in which was secreted the deck of cards found on Dr. Xavier’s desk.”
“What?” said Dr. Holmes, astonished. “I didn’t know that.”
“We didn’t advertise it, Doctor. But after Xavier’s murder someone monkeyed with the lock of the wall cabinet in the living room. What was in the wall cabinet? The deck of cards which had come from the scene of Dr. Xavier’s murder. What was the only significant thing about the deck of cards which would, for any reason whatever, justify some one’s tampering with the lock of the cabinet? The fact that its jack of diamonds was missing. But who knew that the jack of diamonds was missing from the first deck? Only two persons: Mark Xavier and the murderer of Dr. John Xavier. But Mark Xavier was dead. Therefore the tampering was done by the murderer.
“Now what could the murderer’s motive in tampering with that cabinet have possibly been? Did he want to steal or destroy the cards? No.”
“How the devil can you say that?” growled the Inspector.
“Because everyone in the house knew there was only one key to the cabinet, that the cabinet contained only the cards, and most important that the sole key was in your possession, dad.” Ellery chuckled grimly. “How does that prove the murderer didn’t want to steal or destroy the cards? It leads to the proof. If the murderer wanted to get his claws on that deck, why didn’t he take the key from you while he had you unconscious, helpless on the floor of Mark Xavier’s bedroom? The answer is that he didn’t want the key, didn’t want to get into the cabinet, didn’t want to steal or destroy the cards!”
“All right, even if that’s so — for heaven’s sake why did he tamper with the cabinet at all if he didn’t want to get in?”
“A very pertinent question. The only possible alternative is that he merely wanted to call attention to the deck of cards. There was even a confirmation of this: his whole effort to break into a metal cabinet with a puny little fire tool showed that his intentions were directional rather than acquisitive.”
“Ill be damned,” said Smith huskily.
“No doubt. At any rate it was evident that the whole thing was a blind, a ruse, a device to call our attention to the first deck, to get us to re-examine it and discover that the jack was missing. But who could have had motive to call our attention to the missing jack? The twins, whom the missing jack accused? Had they tampered with the cabinet it could only have been with the determination to destroy the deck. I’ve just proved that the purpose of the tamperer was to call attention to the deck — the last thing in the world the twins, had they been guilty, would have wanted. Therefore the twins didn’t tamper with the lock. But I’ve also shown that the one who tampered with the lock was the murderer. Therefore, again, the twins — one or both of them — were not the murderer. Therefore, finally, the twins were framed by the murderer... which is what I set out, eons ago, to demonstrate.”