“Why should you be worried?” he asked, a flicker of alarm in his eyes. He knew he was old and dull-witted and absent-minded. He knew by keeping on practicing medicine at his age he ran the risk of making a mistake sooner or later. I could see he thought I was going to accuse him of making that mistake now.

“Well, you see,” I said mildly, not wanting to stampede him, “I’ve been away for three or four years. Janet Crosby was a very old friend. I had no idea she had a bad heart. It was a great shock to me to hear she had gone like that. I want to satisfy myself that there was nothing wrong.”

A muscle in his face twitched. The nostrils dilated.

“What do you mean—wrong? She died of malignant endocarditis. The symptoms are unmistakable. Besides, Dr. Salzer was there. There was nothing wrong. I don’t know what you mean.”

“Well, I’m glad to hear it. What exactly is malignant endocarditis?”

He frowned blankly, and, for a moment, I thought he was going to say he didn’t know, but he got hold of himself, stirred his old withered memory and said slowly as if he were conjuring up a page from some medical dictionary, “It’s a progressive microbic infection of the heart valves. Fragments of the ulcerating valves were carried by the blood stream all over her body. She hadn’t a chance. Even if they had called me in sooner, there was nothing I could have done.”

“That’s what’s worrying me, doc,” I said, and smiled to let him know I was on his side.

“Just why did they call you in? You weren’t her doctor, were you?”

“Certainly not,” he said, almost angrily. “But it was quite proper to call me in. I live close by. It would have been unethical for Dr. Salzer to have issued the certificate.”

“Just who is Dr. Salzer?”