“Ah! I found a joint in your armor that time, didn’t I? Shall I tell you what you did at the hotel?”
But the head of St. Swithin’s held himself once more with a tight rein. He leaned back in his chair and folded his arms.
“I’m afraid you misinterpreted my exclamation,” he said. “It was called out not by guilt, but by astonishment and concern. My confidence in your sanity has received a big jolt, Carter. I’ve been treated to many such flights of the imagination, but I never expected to find you indulging in them. Professionally, though, your condition appeals to me, and I’m tempted to humor you; therefore, go on by all means, and tell me what I did at the—what hotel did you say it was?”
“Cut it out, Follansbee,” the detective advised, ignoring the question. “You’ve given yourself away, and it’s a waste of cleverness to try to cover up the break now. I’ll accept your invitation, though, and tell you what you did. In the first place, you were unconventional enough to choose the fire escape as a means of access to Stone’s room.”
He did not look into Follansbee’s eyes, but fastened his gaze on the man’s right temple. The eyes would have told him nothing, but there was a blue, distended vein in that temple, and its throbbing was significant.
“You and your patient—your tool—used a painter’s ladder to reach the fire escape,” the detective went on, “and when you had climbed to Stone’s room, on the second floor, you neglected to remove a little wedge of wood on the sill which prevented the sash from closing.”
He leaned farther forward, and his voice was the voice of a judge. “Thanks to that little oversight, Follansbee,” he continued, “I was able to hear all that you said. I heard from your own lips about the hypodermic syringe, and the character of its contents, as well as about the drug which you gave to Stone to——
“Keep your hands up!”