I found Griselda in the drawing-room. She looked frightened, but excited.
I told her everything and she listened attentively.
“The letter is headed 6:20,” I ended. “And the clock fell over and has stopped at 6:22.”
“Yes,” said Griselda. “But that clock, didn’t you tell him that it was always kept a quarter of an hour fast?”
“No,” I said. “I didn’t. He wouldn’t let me. I tried my best.”
Griselda was frowning in a puzzled manner.
“But, Len,” she said, “that makes the whole thing perfectly extraordinary. Because when that clock said twenty past six it was really only five minutes past, and at five minutes past I don’t suppose Colonel Protheroe had even arrived at the house.”