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.”
“Because he was writing at the desk,” I said.
“And that’s what’s all wrong. That was at twenty past six. We agreed that he wouldn’t sit down to say he couldn’t wait any longer until after half-past six—so, why was he sitting at the writing-table then?”