"You're about the same height and build as the dead man, are you, and you were wearing a woollen scarf round your neck just as he was?"

"I fail to see—" began Mr. Downes stiffly.

"I'm telling you, man," said Colonel Anderson, "just where your luck came in. Somehow or other, when the murderer followed you in, he got confused. He picked on the wrong back. I'll eat my hat, Mr. Downes, if that knife wasn't meant for you!"

However well Mr. Downes' heart had stood former tests, it was unable to stand up to this one. Mr. Downes sank on a chair, gasped, and turned purple in the face.

"Water," he gasped. "Water . . . ."

A glass was brought him. He sipped it whilst his complexion gradually returned to normal.

"Me?" he said. "Why me?"

"It looks like it," said Crome. "In fact, it's the only explanation."

"You mean that this man—this—this fiend incarnate—this bloodthirsty madman has been following me about waiting for an opportunity?''

"I should say that was the way of it."

"But in heaven's name, why me?" demanded the outraged schoolmaster.

Inspector Crome struggled with the temptation to reply: "Why not?" and said instead: "I'm afraid it's no good expecting a lunatic to have reasons for what he does."

"God bless my soul," said Mr. Downes, sobered into whispering. He got up. He looked suddenly old and shaken.

"If you don't want me anymore, gentlemen, I think I'll go home. I—I don't feel very well."

"That's quite all right, Mr. Downes. I'll send a constable with you—just to see you're all right."

"Oh, no—no, thank you. That's not necessary."

"Might as well," said Colonel Anderson gruffly. His eyes slid sideways, asking an imperceptible question of the inspector.

The latter gave an equally imperceptible nod.

Mr. Downes went out shakily.

"Just as well he didn't tumble to it," said Colonel Anderson.

"There'll be a couple of them—eh?"

"Yes, sir. Your Inspector Rice has made arrangements. The house will be watched."

"You think," said Poirot, "that when A.B.C. finds out his mistake he might try again?"

Anderson nodded. "It's a possibility," he said. "Seems a methodical sort of chap, A.B.C.. It will upset him if things don't go according to programme."

Poirot nodded thoughtfully.

"Wish we could get a description of the fellow," said Colonel Anderson irritably. "We're as much in the dark as ever."

"It may come," said Poirot.

"Think so? Well, it's possible. Damn it all, hasn't anyone got eyes in his head?"

"Have patience," said Poirot.

"You seem very confident, M. Poirot. Got any reason for this optimism?''

"Yes, Colonel Anderson. Up to now, the murderer has not made a mistake. He is bound to make one soon."

"If that's all you've got to go on," began the Chief Constable with a snort, but he was interrupted.

"Mr. Ball of the Black Swan is here with a young woman, sir. He reckons he's got summat to say might help you."

"Bring them along. Bring them along. We can do with anything helpful."

Mr. Ball of the Black Swan was a large, slow-thinking, heavily-moving man. He exhaled a strong odour of beer. With him was a plump young woman with round eyes clearly in a state of high excitement.

"Hope I'm not intruding or wasting valuable time," said Mr. Ball in a slow, thick voice. "But this wench, Mary here, reckons she's got something to tell as you ought to know."

Mary giggled in a half-hearted way.

"Well, my girl, what is it?" said Anderson. "What's your name?"

"Mary, sir—Mary Stroud."

"Well, Mary, out with it."

Mary turned her round eyes on her master.

"It's her business to take up hot water to the gents' bedrooms," said Mr. Ball, coming to the rescue. "About half a dozen gentlemen we've got staying. Some for the races and some just commercials."

"Yes, yes," said Anderson impatiently.

"Get on, lass," said Mr. Ball. "Tell your tale. Nothing to be afraid of."

Mary gasped, groaned and plunged in a breathless voice into her narrative.

"I knocked on door and there wasn't no answer, otherwise I wouldn't have gone in leastways not unless gentleman had said 'Come in,' and as he didn't say nothing I went in and he was there washing his hands."

She paused and breathed deeply.

"Go on, my girl," said Anderson.

Mary looked sideways at her master and as though receiving inspiration from his slow nod, plunged on again.

"'It's your hot water, sir,' I said, 'and I did knock,' but 'Oh,' he says, 'I've washed in cold,' he said, and so, naturally, I looks in basin, and oh! God help me, sir, it were all red!"

"Red?" said Anderson sharply.

Ball struck in. "The lass told me that he had his coat off and that he was holding the sleeve of it, and it was all wet—that's right, eh, lass?"

"Yes, sir, that's right, sir."

She plunged on: "And his face, sir, it looked queer, mortal queer it looked. Gave me quite a turn."

"When was this?" asked Anderson sharply.

"About a quarter after five, so near as I can reckon."

"Over three hours ago," snapped Anderson. "Why didn't you come at once?"

"Didn't hear about it at once," said Ball. "Not till news came along as there'd been another murder done. And then the lass she screams out as it might have been blood in the basin, and I asked her what she means, and she tells me. Well, it doesn't sound right to me and I went upstairs myself. Nobody in the room. I asks a few questions and one of the lads in courtyard says he saw a fellow sneaking out that way and by his description it was the right one. So I says to the missus as Mary here had best go to police. She doesn't like the idea, Mary doesn't, and I says I'll come along with her."

Inspector Crome drew a sheet of paper towards him.

"Describe this man," he said. "As quick as you can. There's no time to be lost."

"Medium-sized, he were," said Mary. "And stooped and wore glasses.''

"His clothes?"

"A dark suit and a Homburg hat. Rather shabby-looking."

She could add little to this description.

Inspector Crome did not insist unduly. The telephone wires were soon busy, but neither the inspector nor the Chief Constable were overoptimistic.

Crome elicited the fact that the man, when seen sneaking across the yard, had had no bag or suitcase. "There's a chance there," he said.

Two men were dispatched to the Black Swan.

Mr. Ball, swelling with pride and importance, and Mary, somewhat tearful, accompanied them.

The sergeant returned about ten minutes later.

"I've brought the register, sir," he said. "Here's the signature."

We crowded round. The writing was small and cramped—not easy to read.

"A.B.Case—or is it Cash?" said the Chief Constable.

"A.B.C.," said Crome significantly.

"What about luggage?" asked Anderson.

"One good-sized suitcase, sir, full of small cardboard boxes."

"Boxes? What was in 'em?"

"Stockings, sir. Silk stockings."

Crome turned to Poirot. "Congratulations," he said. "Your hunch was right."