“I remember quite well, and you took all the medicine bottles away. You said you wanted to work up your case. What is it, Luke, what is the matter?”

“Something very grave has happened,” he replied. “I have hesitated for some weeks to tell you. The fact is, I have known this for over a month; my wife also knows it, for I had to confide in her. For a time I thought I would keep the whole matter to myself, but I found that my conscience would not rest. It seems to me you ought to know, that you are the one to decide. The thing haunts me. I can bear it no longer. That is the reason why I could not come to Pelham Towers to talk the matter over with you, for it concerns—Richard Pelham.”

“But what is it, Luke? I wish you would speak out. I hate people to beat about the bush. You have discovered something in the bottle of medicine. By the way, Dick was very queer when he spoke about that medicine.”

“No wonder,” said Tarbot. “He came to you about it, then? Yes, I remember, he told me so.”

“He did. He said he wanted to get the medicine analyzed. It was a strange wish of his, and it puzzled me at the time. Just as if the dear child had come by his death by foul means! Luke, what is it?”

Mrs. Pelham had been seated. Now she stood upright, for something in the face of the doctor had overbalanced her self-control. Holding out both her hands, she clasped those of Luke Tarbot.

“Sit down; control yourself,” he said. “I have bad news. I analyzed the medicine. I found hyocene in it.”

“Hyocene? What is that?”

“A deadly poison.”

“Luke!”