XXIIMr. Carroll came into the study with a jaunty air. The cold blue eyes of Sergeant Abbott took him in from head to foot. Their owner decided that the fellow was putting on an act. Might mean nothing—putting on acts being more or less second nature to an actor. Might mean something to hide—according to Pearson, quite a lot. He sustained a slightly insolent return stare with equanimity and took up his pencil. Mr. Carroll’s act, which permitted a derogatory glance at the Sergeant, tumbled over itself with bright helpfulness towards the Chief Inspector. “You’ll understand I don’t know any of these people except Miss Lane—I’ve met her of course. But anything I can do to be of any help——” “I take it you knew Mr. Porlock?” Mr. Carroll’s crooked eyebrow rose. “As a matter of fact, hardly a

