“I should have thought your own knowledge was amply sufficient to answer that question, Cassilis. In ordinary circumstances, no; quite the contrary, the dose would fail even to produce the effect intended; it would hardly render the victim insensible. But suppose that he had just taken his maximum dose, and the extra quantity was administered immediately after, then the effect might be very serious, indeed.” Somehow I felt that I was being fenced with. Tarleton must have perceived a lack of candour on my part in discussing the problem, and decided to withhold his confidence for the time being. I had to remind myself of the admissions I had been driven to make in the course of the morning. My chief knew that I had been a visitor to the Domino Club on one occasion. He knew that I had heard something of Dr. Weathered, and heard it in confidence, as he supposed, or affected to believe, from a patient of my own. He must have put two and two together by this time. Some inkling of the truth must be in his mind. It did not call for very much acuteness on his part to see in me the confidential adviser of one of Weathered’s patients--perhaps one of his victims--possibly of the very one who had administered the fatal dose, and carried off the incriminating book. I resolved to hold my tongue for the future. I would make no more attempts to sound Sir Frank, and would trust to his respect for professional secrecy to protect me from any awkward questions from him. The resolution was easier to take than to keep. As soon as lunch was over the consultant led the way upstairs to his study. It appeared that the autopsy was to be postponed; the first business was to be the examination of the books that Madame Bonnell had been so unwilling to give up. The physician seated himself at his massive bureau, a combination of desk and cabinet, and drew the volume labelled “_Members_” in front of him, while I placed myself respectfully on a chair at the side. “The list of members isn’t a very large one,” was his first observation. “One could hardly expect it to be. The Domino Club has more the character of a secret society than a club; a society for the pursuit of illicit pleasures, let us say. Whom have we here?” He opened the book as he spoke, and ran his eye slowly down the first page. “The Duke of Altringham--I am not surprised at seeing his name; General Sir Francis Uppingham, K.C.B.; the Countess of Eardisley; Honourable Janet Wilbraham; Mrs. Worboise; Sir George Castleton, Bart.--h’m, we are beginning to come across some of the names in the appointment-book, but I don’t see anything to account for the numbers attached to them. And I shall be very much surprised if those numbers don’t contain the true key to the mystery.”