"No, not that," said the reporter, and his face flushed under the close questioning. "He was out of the suite every night."
"Therefore might have been the very one who turned on the gas," the other put in testily.
"So far as I can learn, nobody could have gone into that room and turned on the gas," said the reporter, somewhat aggressively. "Henley barred the doors and windows and kept watch, night after night."
"Yet the moment he was exhausted and fell asleep the gas was turned on to kill him," said The Thinking Machine; "thus we see that _he was watched more closely than he watched_."
"I see what you mean now," said Hatch, after a long pause.
"I should like to know what Henley and Cabell and the valet knew of the girl who was found dead," The Thinking Machine suggested. "Further, I should like to know if there was a good-sized mirror--not one set in a bureau or dresser--either in Henley's room or the apartments where the girl was found. Find out this for me and--never mind. I'll go with you."
The scientist left the room. When he returned he wore his coat and hat. Hatch arose mechanically to follow. For a block or more they walked along, neither speaking. The Thinking Machine was the first to break the silence:
"You believe Cabell is the man who attempted to kill Henley?"
"Frankly, yes," replied the newspaper man.
"Why?"