“ Point No. 4 ⁠—The person with Mr. Ackroyd at nine-thirty was asking for money. We know Ralph Paton was in a scrape.

“ These four points go to show that the person with Mr. Ackroyd at nine-thirty was Ralph Paton. But we know that Mr. Ackroyd was alive at a quarter to ten, therefore it was not Ralph who killed him. Ralph left the window open. Afterwards the murderer came in that way. ”

“And who was the murderer?” inquired Poirot.