Speeding a little, he passed along the rear of it, crossed a slightly brighter space, and gained the shadow of the next one. But as he reached the further corner a sound, slight yet unmistakeable, brought him to a sudden halt, breathless and tingling. The sound was the faint splintering of wood, and close upon its heels came the noise of a window being slowly lifted. With nerves like taut-strung wires, Steve crept forward and peered around the corner.