“Ah!” said the other man. “You think that, do you?”

Pender waited for him to elaborate this remark, but nothing came of it. The man leaned back and smiled in his secret way at the roof of the carriage; he appeared to think the conversation not worth going on with. Pender found himself noticing his companion’s hands.

They were white and surprisingly long in the fingers. He watched them gently tapping upon their owner’s knee — then resolutely turned a page — then put the book down once more and said:

“Well, if it’s so easy, how would you set about committing a murder?”

“I?” repeated the man. The light on his glasses made his eyes quite blank to Pender, but his voice sounded gently amused. “That’s different; I should not have to think twice about it.”

“Why not?”

“Because I happen to know how to do it.”

“Do you indeed?” muttered Pender, rebelliously.

“Oh yes; there’s nothing to it.”

“How can you be sure? You haven’t tried, I suppose?”

“It isn’t a case of trying,” said the man. “There’s nothing uncertain about my method. That’s just the beauty of it.”

“It’s easy to say that,” retorted Pender, “but what is this wonderful method?”

“You can’t expect me to tell you that, can you?” said the other man, bringing his eyes back to rest on Pender’s. “It might not be safe. You look harmless enough, but who could look more harmless than Crippen? Nobody is fit to be trusted with absolute control over other people’s lives.”

“Bosh!” exclaimed Pender. “I shouldn’t think of murdering anybody.”

“Oh yes you would,” said the other man, “if you really believed it was safe. So would anybody. Why are all these tremendous artificial barriers built up around murder by the Church and the law?

Just because it’s everybody’s crime and just as natural as breathing.”