She shook her head.
"I don't want to think about that," she said; "please don't let us talk about it."
He knew she was referring to John Minute's death, and changed the conversation.
A few minutes later he had an opportunity of speaking with Mr. Mann.
"What is the news?" he asked.
Saul Arthur Mann looked round.
"I think we are getting near the truth," he said, dropping his voice. "One of my men has had him under observation ever since the day of the trial. There is no doubt that he is really a brilliant chemist."
"Have you a theory?"
"I have several," said Mr. Mann. "I am perfectly satisfied that the unfortunate fellow we saw together on the occasion of our first meeting was Rex Holland's servant. I was as certain that he was poisoned by a very powerful poisoning. When your trial was on the body was exhumed and examined, and the presence of that drug was discovered. It was the same as that employed in the case of the chauffeur. Obviously, Rex Holland is a clever chemist. I wanted to see you about that. He said at the trial that he had discussed such matters with you."