“Really, y’ know, Markham, old thing,” he added, “you should study the cranial indications of your fellow man more carefully—vultus est index animi. Did you, by any chance, note the gentleman’s wide rectangular forehead, his irregular eyebrows, and pale luminous eyes, and his outstanding ears with their thin upper rims, their pointed tragi and split lobes? . . . A clever devil, this Ambroise—but a moral imbecile. Beware of those pseudo-pyriform faces, Markham; leave their Apollonian Greek suggestiveness to misunderstood women.”

“I wonder what he really knows?” grumbled Markham irritably.

“Oh, he knows something—rest assured of that! And if only we knew it, too, we’d be considerably further along in the investigation. Furthermore, the information he is hiding is somewhat unpleasantly connected with himself. His euphoria is a bit shaken. He frightfully overdid the grand manner; his valedict’ry fulmination was the true expression of his feeling toward us.”

“Yes,” agreed Markham. “That question about last night acted like a petard. What prompted you to suggest my asking it?”

“A number of things—his gratuitous and obviously mendacious statement that he had just read of the murder; his wholly insincere homily on the sacredness of professional confidences; the cautious and Pecksniffian confession of his fatherly regard for the girl; his elaborate struggle to remember when he had last seen her—this particularly, I think, made me suspicious; and then, the psychopathic indicants of his physiognomy.”

“Well,” admitted Markham, “the question had its effect. . . . I feel that I shall see this fashionable M.D. again.”

“You will,” iterated Vance. “We took him unawares. But when he has had time to ponder the matter and concoct an appealin’ tale, he’ll become downright garrulous. . . . Anyhow, the evening is over, and you can meditate on buttercups till the morrow.”

But the evening was not quite over as far as the Odell case was concerned. We had been back in the lounge-room of the club but a short time when a man walked by the corner in which we sat, and bowed with formal courtesy to Markham. Markham, to my surprise, rose and greeted him, at the same time indicating a chair.

“There’s something further I wanted to ask you, Mr. Spotswoode,” he said, “if you can spare a moment.”

At the mention of the name I regarded the man closely, for, I confess, I was not a little curious about the anonymous escort who had taken the girl to dinner and the theatre the night before. Spotswoode was a typical New England aristocrat, inflexible, slow in his movements, reserved, and quietly but modishly dressed. His hair and moustache were slightly gray—which, no doubt, enhanced the pinkness of his complexion. He was just under six feet tall, and well proportioned, but a trifle angular.