"All right; if I am compelled to do so," rejoined Sidney. "The mine runs away to your left--two hundred yards, I should think." In point of fact, and Private Bartlett was perfectly aware of it, the explosion chamber was almost immediately beyond that part of the hostile trench in which he was held prisoner. Although the main force of the explosion would be directed against the Pumpnickel Redoubt there was the almost certainty of a swift and terrible death to every living creature in the German first-line trenches as well. The Hun officer snapped out some words of command to his men. The soldiers began to pile up sand-bags across the trench to neutralize, as they thought, the outlying effects of the impending explosion, while the locality that Bartlett had purposely and wrongly indicated was cleared of troops. "Ach!" continued the Major. "Now you vos tell me dis: at vot hour the mine goes it off?" "At six-thirty," replied Sidney promptly. He was entering eagerly into the "business" by this time. It would result, he had no doubt, in the extermination of several hundred Germans and his comparatively insignificant self as well. "Now, we see," remarked the Prussian officer. "If der truth you haf said, den all vill well be. We keep you here--in der drench." Evidently the German had certain misgivings, for, ordering a post to be driven deeply into the slime and his prisoner to be firmly bound to it, he scurried off to a remote portion of the reserve trenches. This much Ralph Setley heard. From other sounds he came to the conclusion that most, if not all, of the German troops were following their superior's example. "Time for me to be getting back," he soliloquized. "There may yet be an opportunity for our chaps to raid the trench and rescue Bartlett before the mine is sprung. Wonder how time goes? It seems as if I've been out for a couple of hours." He returned in quicker time than he had taken to crawl out to the barbed wire entanglements. For one thing the Huns were no longer in the trench, ready to train a machine-gun on any moving object that they were able to discern in the glare of the star-shells. For another thing, the artillery duel had increased in violence, the rain of projectiles from the British guns being unmistakably superior in velocity to that of the Huns. Perhaps it was a prelude to the impending advance? If so, the hour fixed for the firing of the mine was at hand. "That you, Setley?" came a hoarse whisper almost into his ear. "Yes," replied Ralph, recognizing Alderhame's voice. "Thought you had been done in. We've been back some time. I crawled out to see if I could find you. Come along." A rifle-bullet whizzed past Setley's head. Promptly he ducked and crouched in a convenient shell-hole. Somewhere in No Man's Land a Hun sniper was on the qui vive.