"I feel that you must be wondering why - why I am so interested in all this. You may possibly think it's very unwomanly. No - please - I should like to explain if I may."

She paused a moment, a pink colour suffusing her cheeks.

"You see," she began at last, "living alone, as I do, in a rather out-of-the-way part of the world one has to have a hobby. There is, of course, woolwork, and Guides, and Welfare, and sketching, but my hobby is - and always has been - Human Nature. So varied - and so very fascinating. And, of course, in a small village, with nothing to distract one, one has such ample opportunity for becoming what I might call proficient in one's study. One begins to class people, quite definitely, just as though they were birds or flowers, group so-and-so, genus this, species that. Sometimes, of course, one makes mistakes, but less and less as time goes on. And then, too, one tests on oneself. One takes a little problem - for instance, the gill of picked shrimps that amused dear Griselda so much - a quite unimportant mystery but absolutely incomprehensible unless one solves it right. And then there was that matter of the changed cough drops, and the butcher's wife's umbrella - the last absolutely meaningless unless on the assumption that the greengrocer was not behaving at all nicely with the chemist's wife - which, of course, turned out to be the case. It is so fascinating, you know, to apply one's judgment and find that one is right."

"You usually are, I believe," I said, smiling.

"That, I am afraid, is what has made me a little conceited," confessed Miss Marple. "But I have always wondered whether, if some day a really big mystery came along, I should be able to do the same thing. I mean - just solve it correctly. Logically, it ought to be exactly the same thing. After all, a tiny working model of a torpedo is just the same as a real torpedo."

"You mean it's all a question of relativity," I said slowly. "It should be - logically, I admit. But I don't know whether it really is."

"Surely it must be the same," said Miss Marple. "The - what one used to call the factors at school - are the same. There's money, and mutual attraction between people of an - er - opposite sex - and there's queerness, of course - so many people are a little queer, aren't they? - in fact, most people are when you know them well. And normal people do such astonishing things sometimes, and abnormal people are sometimes so very sane and ordinary. In fact, the only way is to compare people with other people you have known or come across. You'd be surprised if you knew how very few distinct types there are in all."

"You frighten me," I said. "I feel I'm being put under the microscope."

"Of course, I wouldn't dream of saying any of this to Colonel Melchett - such an autocratic man, isn't he? - and poor Inspector Slack - well, he's exactly like the young lady in the boot shop; who wants to sell you patent leather because she's got it in your size, and doesn't take any notice of the fact that you want brown calf."

That, really, is a very good description of Slack.

"But you, Mr. Clement, know, I'm sure, quite as much about the crime as Inspector Slack. I thought, if we could work together -"

"I wonder," I said. "I think each one of us in his secret heart fancies himself as Sherlock Homes."

Then I told her of the three summonses I had received that afternoon. I told her of Anne's discovery of the picture with the slashed face. I also told her of Miss Cram's attitude at the police station, and I described Haydock's identification of the crystal I had picked up.

"Having found that myself," I finished up, "I should like it to be important. But it's probably got nothing to do with the case."

"I have been reading a lot of American detective stories from the library lately," said Miss Marple, "hoping to find them helpful."

"Was there anything in them about picric acid?''

"I'm afraid not. I do remember reading a story once, though, in which a man was poisoned by picric acid and lanoline being rubbed on him as an ointment."

"But as nobody has been poisoned here, that doesn't seem to enter into the question," I said.

Then I took up my schedule and handed it to her.

"I've tried," I said, "to recapitulate the facts of the case as clearly as possible."

Thursday, 21st inst.

12.30 a.m. - Colonel Protheroe alters his appointment from six to six-fifteen. Overheard by half village very probably.

12.45 - Pistol last seen in its proper place. (But this is doubtful, as Mrs. Archer had previously said she could not remember.)

5.30 (approx.) - Colonel and Mrs. Protheroe leave Old Hall for village in car.

5.30 - Fake call put through to me from the North Lodge, Old Hall.

6.15 (or a minute or two earlier) - Colonel Protheroe arrives at Vicarage. Is shown into study by Mary.

6.20 - Mrs. Protheroe comes along back lane and across garden to study window. Colonel Protheroe not visible.

6.29 - Call from Lawrence Redding's cottage put through to Mrs. Price Ridley (according to Exchange).

6.30-6.35 - Shot heard. (Accepting telephone call time as correct.) Lawrence Redding, Anne Protheroe and Dr. Stone's evidence seem to point to its being earlier, but Mrs. P. R. probably right.

6.45 - Lawrence Redding arrives at Vicarage and finds the body.

6.48 - I meet Lawrence Redding.

6.49 - Body discovered by me.

6.55 - Haydock examines body.

NOTE. - The only two people who have no kind of alibi for 6.30-6.35 are Miss Cram and Mrs. Lestrange. Miss Cram says she was at the barrow, but no confirmation. It seems reasonable, however, to dismiss her from case as there seems nothing to connect her with it. Mrs. Lestrange left Dr. Haydock's house some time after six to keep an appointment. Where was the appointment, and with whom? It could hardly have been with Colonel Protheroe, as he expected to be engaged with me. It is true that Mrs. Lestrange was near the spot at the time the crime was committed, but it seems doubtful what motive she could have had for murdering him. She did not gain by his death, and the inspector's theory of blackmail I cannot accept. Mrs. Lestrange is not that kind of woman. Also it seems unlikely that she should have got hold of Lawrence Redding's pistol.

"Very clear," said Miss Marple, nodding her head in approval. "Very clear indeed. Gentlemen always make such excellent memoranda."

"You agree with what I have written?" I asked.

"Oh, yes - you have put it all beautifully."

I asked her the question then that I had been meaning to put all along.

"Miss Marple," I said. "Who do you suspect? You once said that there were seven people."

"Quite that, I should think," said Miss Marple absently. "I expect every one of us suspects someone different. In fact, one can see they do."

She didn't ask me who I suspected.

"The point is," she said, "that one must provide an explanation for everything. Each thing has got to be explained away satisfactorily. If you have a theory that fits every fact - well, then, it must be the right one. But that's extremely difficult. If it wasn't for that note -"

"The note?" I said, surprised.

"Yes, you remember, I told you. That note has worried me all along. It's wrong, somehow."

"Surely," I said, "that is explained now. It was written at six thirty-five and another hand - the murderer's - put the misleading 6.20 at the top. I think that is clearly established."

"But even then," said Miss Marple, "it's all wrong."

"But why?"

"Listen." Miss Marple leant forward eagerly. "Mrs. Protheroe passed my garden, as I told you, and she went as far as the study window and she looked in and she didn't see Colonel Protheroe."