“The last two years he’s been in the Asylum,” I said. “But what of the three years before that?”

Poirot shook his head, and then caught my arm.

“The clock, Hastings, look at the clock.”

I followed his gaze to the mantelpiece. The clock had stopped at four o’clock.

“ Mon ami , someone has tampered with it. It had still three days to run. It is an eight-day clock, you comprehend?”

“But what should they want to do that for? Some idea of a false scent by making the crime appear to have taken place at four o’clock?”