"I knew I was goin' to crack your poker-face sooner or later," declared H.M. Then his tone changed. "You didn't work it," he explained patiently, "because you. were instinctively afraid of hurtin' yourself. You jabbed it in with a little bit of a push to see if you would feel it, and so of course you did. That's not the way, son. Your subconscious—"
"Everything in this ruddy case," said Masters, "is subconscious. Look here, sir: this trick really works?"
"Oh, son, of course it does. You saw me do it. Wants practice and strength of mind, naturally."
Masters eyed him.
"You're full of tricks, aren't you?"
"He is," said Courtney, plucking the pin from a smarting arm. "If you were taking down his memoirs, Chief Inspector, you'd realize that that's all he ever thinks about."
H.M. looked pleased.
"I've got a theory," Courtney pursued, "that it's the explanation of how he catches murderers. His mind works like theirs."
"But the point is," insisted Masters, sweeping this aside, "that this thing is practical and Mrs. Fane could have been shamming. Hold on, though! It was Dr. Rich who worked that game. Does that mean he was in cahoots with her?"
"No, no, no, no, no!" growled H.M. "It doesn't mean Mrs. Fane was shamming, and it doesn't mean Rich was in cahoots with her. Rich knew very well she wasn't shamming—"