I sprang from my chair in simulated anger.

“This is intolerable, sir,” said I. “I came here to do you a favour, and not to be examined as if I were a schoolboy. My knowledge on these subjects may be second only to your own, but I certainly shall not answer questions which have been put in so offensive a way.”

He looked at me steadily. The languor had gone from his eyes. They suddenly glared. There was a gleam of teeth from between those cruel lips.

“What is the game? You are here as a spy. You are an emissary of Holmes. This is a trick that you are playing upon me. The fellow is dying, I hear, so he sends his tools to keep watch upon me. You’ve made your way in here without leave, and, by God! you may find it harder to get out than to get in.”