Pen merely looked at him.

"Answer my question, please!"

"I have already answered it."

"Do you expect me to believe that you undertook to save a total stranger from the law?"

"I have stated the facts."

The detective sprang to his feet and shook a violent forefinger at Pen—the old trick of the inquisitor. "You have seen this man before!"

"Don't shout at me," said Pen coolly. "I am not a criminal."

"As to that we'll see," he said ominously. "Did you ever hear of accessory after the fact."

"Well, if I am a criminal," said Pen, "I don't have to testify against myself."

"Don't argue with me if you please," he said. "Just answer my questions."