He rang off, fuming.

"Wrong number, wrong number - always wrong numbers! And a man's life hanging on it. HALLO - you gave me the wrong number… Yes - don't waste time - give me three nine - nine, not five."

Another period of impatience - shorter this time.

"Hallo - is that you, Haydock? Melchett speaking. Come to 19 High Street at once, will you? Hawes has taken some kind of overdose. At once, man, it's vital."

He rang off, strode impatiently up and down the room.

"Why on earth you didn't get hold of the doctor at once, Clement, I cannot think. Your wits must have all gone wool gathering."

Fortunately it never occurs to Melchett that any one can possibly have any different ideas on conduct to those he holds himself, I said nothing, and he went on:

"Where did you find this letter?"

"Crumpled on the door - where it had fallen from his hand."

"Extraordinary business - that old maid was right about its being the wrong note we found. Wonder how she tumbled to that. But what an ass the fellow was not to destroy this one. Fancy keeping it - the most damaging evidence you can imagine!"

"Human nature is full of inconsistencies."

"If it weren't, I doubt if we should ever catch a murderer! Sooner or later they always do some fool thing. You're looking very under the weather, Clement. I suppose this has been the most awful shock to you?"

"It has. As I say, Hawes has been queer in his manner for some time, but I never dreamed -"

"Who would? Hallo, that sounds like a car." He went across to the window, pushing up the sash and leaning out. "Yes, it's Haydock all right."

A moment later the doctor entered the room.

In a few succinct words Melchett explained the situation.

Haydock is not a man who ever shows his feelings. He merely raised his eyebrows, nodded, and strode across to his patient. He felt his pulse, raised the eyelid and looked intently at the eye.

Then he turned to Melchett.

"Want to save him for the gallows?" he asked. "He's pretty far gone, you know. It will be touch and go, anyway. I doubt if I can bring him round."

"Do everything possible."

"Right."

He busied himself with the case he had brought with him, preparing a hypodermic injection which he injected into Hawes's arm. Then he stood up.

"Best thing is to run him into Much Benham - to the hospital there. Give me a hand to get him down to the car."

We both lent our assistance. As Haydock climbed into the driving seat, he threw a parting remark over his shoulder.

"You won't be able to hang him, you know, Melchett."

"You mean he won't recover?"

"May or may not. I didn't mean that. I mean that even if he does recover - well, the poor devil wasn't responsible for his actions. I shall give evidence to that effect."

"What did he mean by that?" asked Melchett as we went upstairs again.

I explained that Hawes had been a victim of encephalitis lethargica.

"Sleepy sickness, eh? Always some good reason nowadays for every dirty action that's done. Don't you agree?"

"Science is teaching us a lot."

"Science be damned - I beg your pardon, Clement; but all this namby pambyism annoys me. I'm a plain man. Well, I suppose we'd better have a look round here."

But at this moment there was an interruption - and a most amazing one. The door opened and Miss Marple walked into the room.

She was pink and somewhat flustered, and seemed to realise our condition of bewilderment.

"So sorry - so very sorry - to intrude - good-evening, Colonel Melchett. As I say, I am so sorry, but hearing that Mr. Hawes was taken in, I felt I must come round and see if I couldn't do something."

She paused. Colonel Melchett was regarding her in a somewhat disgusted fashion.

"Very kind of you, Miss Marple," he said dryly. "But no need to trouble. How did you know, by the way?"

It was the question I had been yearning to ask!

"The telephone," explained Miss Marple. "So careless with their wrong numbers, aren't they? You spoke to me first, thinking I was Dr. Haydock. My number is three five."

"So that was it!" I exclaimed.

There is always some perfectly good and reasonable explanation for Miss Marple's omniscience.

"And so," she continued. "I just came round to see if I could be of any use."

"Very kind of you," said Melchett again, even more dryly this time. "But nothing to be done. Haydock's taken him off to hospital."

"Actually to hospital? Oh, that's a great relief! I am so very glad to hear it. He'll be quite safe there. When you say 'nothing to be done,' you don't mean that there's nothing to be done for him, do you? You don't mean that he won't recover?"

"It's very doubtful," I said.

Miss Marple's eyes had gone to the cachet box.

"I suppose he took an overdose?" she said.

Melchett, I think, was In favour of being reticent. Perhaps I might have been under other circumstances. But my discussion of the case with Miss Marple was too fresh in my mind for me to have the same view, though I must admit that her rapid appearance on the scene and eager curiosity repelled me slightly.

"You had better look at this," I said, and handed her Protheroe's unfinished letter.

She took it and read it without any appearance of surprise.

"You had already deduced something of the kind, had you not?" I asked.

"Yes - yes, indeed. May I ask you, Mr. Clement, what made you come here this evening? That is a point which puzzles me. You and Colonel Melchett - not at all what I should have expected."

I explained the telephone call and that I believed I had recognised Hawes's voice. Miss Marple nodded thoughtfully.

"Very interesting. Very providential - if I may use the term. Yes, it brought you here in the nick of time."

"In the nick of time for what?" I said bitterly.

Miss Marple looked surprised.

"To save Mr. Hawes's life, of course."

"Don't you think," I said, "that it might be better if Hawes didn't recover? Better for him - better for every one. We know the truth now and -"

I stopped - for Miss Marple was nodding her head with such a peculiar vehemence that it made me lose the thread of what I was saying.

"Of course," she said. "Of course! That's what he wants you to think! That you know the truth - and that it's best for every one as it is. Oh, yes, it all fits in - the letter, and the overdose, and poor Mr. Hawes's state of mind and his confession. It all fits in - but it's wrong…"

We stared at her.

"That's why I am so glad Mr. Hawes is safe - in hospital where no one can get at him. If he recovers, he'll tell you the truth."

"The truth?"

"Yes - that he never touched a hair of Colonel Protheroe's head."

"But the telephone call," I said. "The letter - the overdose. It's all so clear."

"That's what he wants you to think. Oh, he's very clever! Keeping the letter and using it this way was very clever indeed."

"Who do you mean," I said, "by 'he'?"

"I mean the murderer," said Miss Marple.

She added very quietly:

"I mean Mr. Lawrence Redding…"