“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 resumé of the case. She spoke with such certainty that we both felt that in 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