“Along with a few thousand other enigmas—yes,” was the petulant reply. “But the more I try to reason it out, the more of a mystery the whole thing becomes.”

“Loosely put, my dear Markham,” criticized Vance. “There are no mysteries originating in human beings, y’ know; there are only problems. And any problem originating in one human being can be solved by another human being. It merely requires a knowledge of the human mind, and the application of that knowledge to human acts. Simple, what?”

He glanced at the clock.

“I wonder how your Mr. Stitt is getting along with the Benson and Benson books. I await his report with anticipat’ry excitement.”

This was too much for Markham. The wearing-down process of Vance’s intimations and veiled innuendoes had at last dissipated his self-control. He bent forward and struck the desk angrily with his hand.

“I’m damned tired of this superior attitude of yours,” he complained hotly. “Either you know something or you don’t. If you don’t know anything, do me the favor of dropping these insinuations of knowledge. If you do know anything, it’s up to you to tell me. You’ve been hinting around in one way or another ever since Benson was shot. If you’ve got any idea who killed him, I want to know it.”

He leaned back, and took out a cigar. Not once did he look up as he carefully clipped the end and lit it. I think he was a little ashamed at having given way to his anger.

Vance had sat apparently unconcerned during the outburst. At length he stretched his legs, and gave Markham a long contemplative look.

“Y’ know, Markham old bean, I don’t blame you a bit for your unseemly ebullition. The situation has been most provokin’. But now, I fancy, the time has come to put an end to the comedietta. I really haven’t been spoofing, y’ know. The fact is, I’ve some most int’restin’ ideas on the subject.”

He stood up and yawned.