"I would not say a word unless I was sure that you were guilty."

"Even then, why should you speak?"

"There's a conscience, and—"

"Nonsense! What business is it of yours? Now look here; you think a good deal more about money than you do about your conscience. I've got money, and I'm willing to pay well to keep out of trouble."

"But I don't want to get into any."

"You won't. All you've got to do is to keep still."

"Keep still about what, sir?"

"This sleep-walking to-night."

"I won't say a word, unless—"

Nick hesitated. He wished to give the doctor the impression that his innocence was by no means clear, and that the idea of shielding a murderer was not to be entertained.