I studied him quietly without appearing to do so. He was clearly under the influence of some strong excitement. For a minute or two he paced up and down the room, then, as Parker entered with the coffee tray, he sank into an armchair in front of the fire.

The study was a comfortable apartment. Bookshelves lined one wall of it. The chairs were big and covered in dark blue leather. A large desk stood by the window and was covered with papers neatly docketed and filed. On a round table were various magazines and sporting papers.

“I’ve had a return of that pain after food lately,” remarked Ackroyd calmly, as he helped himself to coffee. “You must give me some more of those tablets of yours.”

It struck me that he was anxious to convey the impression that our conference was a medical one. I played up accordingly.

“I thought as much. I brought some up with me.”

“Good man. Hand them over now.”