“Is it an effort of Parker’s imagination? Or is there something in it?”

“If Parker heard anything about blackmail,” I said slowly, “he must have been listening outside this door with his ear glued against the keyhole.”

Davis nodded. “Nothing more likely. You see, I’ve been instituting a few inquiries as to what Parker has been doing with himself this evening. To tell the truth, I didn’t like his manner. The man knows something. When I began to question him, he got the wind up, and plumped out some garbled story of blackmail.”

I took an instant decision. “I’m rather glad you’ve brought the matter up,” I said. “I’ve been trying to decide whether to make a clean breast of things or not. I’d already practically decided to tell you everything, but I was going to wait for a favourable opportunity. You might as well have it now.”

And then and there I narrated the whole events of the evening as I have set them down here. The inspector listened keenly, occasionally interjecting a question.