resemble each other in one thing.”
“What is that?” I asked curiously.
“Everyone concerned in them has something to hide.”
“Have I?” I asked, smiling.
Poirot looked at me attentively. “I think you have,” he said quietly.
“But—”
“Have you told me everything known to you about this young man Paton?” He smiled as I grew red. “Oh! do not fear. I will not press you. I shall learn it in good time.”
“I wish you’d tell me something of your methods,” I said hastily, to cover my confusion. “The point about the fire, for instance?”
“Oh! that was very simple. You leave Mr. Ackroyd at—ten minutes to nine, was it not?”
“Yes, exactly, I should say.”
“The window is then closed and bolted and the door unlocked. At a quarter past ten when the body is discovered, the door is locked and the window is open. Who opened it? Clearly only Mr. Ackroyd himself could have done so, and for one of two reasons. Either because the room became unbearably hot (but since the fire was nearly out and there was a sharp drop in temperature last night, that cannot be the reason), or because he admitted someone that way. And if he admitted someone that way, it must have been someone well known to him, since he had previously shown himself uneasy on the subject of that same window.”
“It sounds very simple,” I said.