bourne Grove district—when his musings were rudely interrupted. Between this terrace and Markendale Square was a narrow passage, little frequented save by residents, or by such folk familiar enough with the neighbourhood to know that it afforded a shortcut. Viner was about to turn into this passage, a dark affair set between high walls, when a young man darted hurriedly out of it, half collided with him, uttered a hasty word of apology, ran across the road and disappeared round the nearest corner. But just there stood a street-lamp, and in its glare Viner caught sight of the hurrying young man's face. And when the retreating footsteps had grown faint, Viner still stood staring in the direction in which they had gone.
"That's strange!" he muttered. "I've seen that chap somewhere—I know him. Now, who is he? And what made him in such a deuce of a hurry?"
It was very quiet at that point. There seemed to be nobody about. Behind him, far down the long, wide terrace, he heard slow, measured steps—that, of course, was a policeman on his beat. But beyond the subdued murmur of the traffic in the Bayswater Road in one direction and in Bishop's Road, Viner heard nothing but those measured steps. And after listening to them for a minute, he turned into the passage out of which the young man had just rushed so unceremoniously.
There was just one lamp in that passage—an old-fashioned affair, fixed against the wall, halfway down. It threw but little light on its surroundings. Those surroundings were ordinary enough. The passage itself was about thirty yards in length. It was in-
