Marlowe rose from his chair and pressed his hands to his eyes. He was flushed with the excitement of his own narrative, and there was in his look a horror of recollection that held both the listeners silent. He shook himself with a movement like a dog’s, and then, his hands behind him, stood erect before the fire as he continued his tale. “I expect you both know what the back-reflector of a motor car is.” Trent nodded quickly, his face alive with anticipation; but Mr. Cupples, who cherished a mild but obstinate prejudice against motor cars, readily confessed to ignorance. “It is a small round or more often rectangular mirror,” Marlowe explained, “rigged out from the right side of the screen in front of the driver, and adjusted in such a way that he can see, without turning round, if anything is coming up behind to pass him. It is quite an ordinary appliance, and there was one on this car. As the car moved on, and Manderson ceased speaking behind me, I saw in that mirror a thing that I wish I could forget.” Marlowe was silent for a moment, staring at the wall before him. “Manderson’s face,” he said in a low tone. “He was standing in the road, looking after me, only a few yards behind, and the moonlight was full on his face. The mirror happened to catch it for an instant. “Physical habit is a wonderful thing. I did not shift hand or foot on the controlling mechanism of the car. Indeed, I dare say it steadied me against the shock to have myself braced to the business of driving. You have read in books, no doubt, of hell looking out of a man’s eyes, but perhaps you don’t know what a good metaphor that is. If I had not known Manderson was there, I should not have recognized the face. It was that of a madman, distorted, hideous in the imbecility of hate, the teeth bared in a simian grin of ferocity and triumph; the eyes.... In the little mirror I had this glimpse of the face alone. I saw nothing of whatever gesture there may have been as that writhing white mask glared after me. And I saw it only for a flash. The car went on, gathering speed, and as it went, my brain, suddenly purged of the vapours of doubt and perplexity, was as busy as the throbbing engine before my feet. I knew.