"Mrs. Protheroe and her husband had just started for the village. And - a very curious thing (though no one happened to think of it that way) - Mrs. Protheroe took no hand-bag with her. Really a most unusual thing for a woman to do. Just before twenty past six she passes my garden and stops and speaks, so as to give me every opportunity of noticing that she has no weapon with her and also that she is quite her normal self. They realised, you see, that I am a noticing kind of person. She disappears round the corner of the house to the study window. The poor colonel is sitting at the desk writing his letter to you. He is deaf, as we all know. She takes the pistol from the bowl where it is waiting for her, comes up behind him and shoots him through the head, throws down the pistol and is out again like a flash, and going down the garden to the studio. Nearly any one would swear that there couldn't have been time!"

"But the shot?" objected the colonel. "You didn't hear the shot?"

"There is, I believe, an invention called a Maxim silencer. So I gather from detective stories. I wonder if, possibly, the sneeze that the maid, Clara, heard might have actually been the shot? But no matter. Mrs. Protheroe is met at the studio by Mr. Redding. They go in together - and, human nature being what it is, I'm afraid they realise that I shan't leave the garden till they come out again!"

I had never liked Miss Marple better than at this moment, with her humorous perception of her own weakness.

"When they do come out, their demeanour is gay and natural. And there, in reality, they made a mistake. Because if they had really said good-bye to each other, as they pretended, they would have looked very different. But you see, that was their weak point. They simply dare not appear upset in any way. For the next ten minutes they are careful to provide themselves with what is called an alibi, I believe. Finally Mr. Redding goes to the Vicarage, leaving it as late as he dares. He probably saw you on the footpath from far away and was able to time matters nicely. He picks up the pistol and the silencer, leaves the forged letter with the time on it written in a different ink and apparently in a different handwriting. When the forgery is discovered it will look like a clumsy attempt to incriminate Anne Protheroe.

"But when he leaves the letter, he finds the one actually written by Colonel Protheroe - something quite unexpected. And being a very intelligent young man, and seeing that this letter may come in very useful to him, he takes it away with him. He alters the hands of the clock to the same time as the letter - knowing that it is always kept a quarter of an hour fast. The same idea - attempt to throw suspicion on Mrs. Protheroe. Then he leaves, meeting you outside the gate, and acting the part of someone nearly distraught. As I say, he is really most intelligent. What would a murderer who had committed a crime try to do? Behave naturally, of course. So that is just what Mr. Redding does not do. He gets rid of the silencer, but marches into the police station with the pistol and makes a perfectly ridiculous self-accusation which takes everybody in."

There was something fascinating in Miss Marple's resumй of the case. She spoke with such certainty that we both felt that this way and in no other could the crime have been committed.

"What about the shot heard in the wood?" I asked. "Was that the coincidence to which you were referring earlier this evening?"

"Oh! dear, no." Miss Marple shook her head briskly. "That wasn't a coincidence - very far from it. It was absolutely necessary that a shot should be heard - otherwise suspicion of Mrs. Protheroe might have continued. How Mr. Redding arranged it, I don't quite know. But I understand that picric acid explodes if you drop a weight on it, and you will remember, dear vicar, that you met Mr. Redding carrying a large stone just in the part of the wood where you picked up that crystal later. Gentlemen are so clever at arranging things - the stone suspended above the crystals and then a time fuse - or do I mean a slow match? Something that would take about twenty minutes to burn through - so that the explosion would come about 6.30 when he and Mrs. Protheroe had come out of the studio and were in full view. A very safe device because what would there be to find afterwards - only a big stone! But even that he tried to remove - when you came upon him."

"I believe you are right," I exclaimed, remembering the start of surprise Lawrence had given on seeing me that day. It had seemed natural enough at the time, but now…

Miss Marple seemed to read my thoughts, for she nodded her head shrewdly.

"Yes," she said, "it must have been a very nasty shock for him to come across you just then. But he turned it off very well - pretending he was bringing it to me for my rock gardens. Only -" Miss Marple became suddenly very emphatic. "It was the wrong sort of stone for my rock gardens! And that put me on the right track!"

All this time Colonel Melchett had sat like a man in a trance. Now he showed signs of coming to. He snorted once or twice, blew his nose in a bewildered fashion, and said:

"Upon my word! Well, upon my word!"

Beyond that, he did not commit himself. I think that he, like myself, was impressed with the logical certainty of Miss Marple's conclusions. But for the moment he was not willing to admit it.

Instead, he stretched out a hand, picked up the crumpled letter and barked out:

"All very well. But how do you account for this fellow Hawes! Why, he actually rang up and confessed."

"Yes, that was what was so providential. The vicar's sermon, doubtless. You know, dear Mr. Clement, you really preached a most remarkable sermon. It must have affected Mr. Hawes deeply. He could bear it no longer, and felt he must confess about the misappropriations of the church funds."

"What?"

"Yes - and that, under Providence, is what has saved his life. (For I hope and trust it is saved. Dr. Haydock is so clever.) As I see the matter, Mr. Redding kept this letter (a risky thing to do, but I expect he hid it in some safe place) and waited till he found out for certain to whom it referred. He soon made quite sure that it was Mr. Hawes. I understand he came back here with Mr. Hawes last night and spent a long time with him. I suspect that he then substituted a cachet of his own for one of Mr. Hawes, and slipped this letter in the pocket of Mr. Hawes's dressing-gown. The poor young man would swallow the fatal cachet in all innocence - after his death his things would be gone through and the letter found and every one would jump to the conclusion that he had shot Colonel Protheroe and taken his own life out of remorse. I rather fancy Mr. Hawes must have found that letter to-night just after taking the fatal cachet. In his disordered state, it must have seemed like something supernatural, and, coming on top of the vicar's sermon, it must have impeded him to confess the whole thing."

"Upon my word," said Colonel Melchett. "Upon my word! Most extraordinary! I - I - don't believe a word of it."

He had never made a statement that sounded more unconvincing. It must have sounded so in his own ears, for he went on:

"And can you explain the other telephone call - the one from Mr. Redding's cottage to Mrs. Price Ridley?"

"Ah!" said Miss Marple. "That is what I call the coincidence. Dear Griselda sent that call - she and Mr. Dennis between them, I fancy. They had heard the rumours Mrs. Price Ridley was circulating about the vicar, and they thought of this (perhaps rather childish) way of silencing her. The coincidence lies in the fact that the call should have been put through at exactly the same time as the fake shot from the wood. It led one to believe that the two must be connected."

I suddenly remembered how every one who spoke of that shot had described it as "different" from the usual shot. They had been right. Yet how hard to explain just in what way the "difference" of the shot consisted.