“Uh-huh,” from Harper, but by this time neither had further breath to spare on conversation. They were forcing themselves forward with every ounce of energy they possessed. As a gray light, barely discernible, loomed in the distance, they knew that at last they were approaching the mouth of the tunnel, and that the first streaks of dawn had appeared. Winded as they were, neither had the strength to climb the smooth-sided hole as the German evidently had done, by the main strength of the pressure of his legs against the walls as he made his way upward. George squared himself with widespread feet, and Tom mounted to his shoulder. Ollie, who was still guarding the prize prisoner and awaiting their return, began popping questions, even as he helped Tom out of the hole, but the latter had no time for more than the essential facts then. “Use your jacket as a rope and give Harper a lift out of that hole,” he instructed, and while this was being done he partially regained his breath. “Now Ollie,” he continued, “go like the wind to the first officer of Engineers you can find, tell him we’ve discovered that everything under Thiaucourt is mined, and get back here with the necessary men as soon as you can.” He turned to Harper. “You stay here and watch this German. I’ve still got breath enough left to make brigade headquarters in a very few minutes. Don’t let Fritz get away under any circumstances.” And at the same instant Tom and Ollie sped away in opposite directions—Tom for the highest commanding officer he could find; Ollie back over the ground they had traversed, past the grave they had dug, and into the wood in search of an officer of Engineers. Both knew that thousands of lives were at stake. Both put forth their bravest effort. For both realized that if they succeeded at all it would only be in the nick of time. ------------------------------------------------------------------------ CHAPTER XII THE DESPERATE CHANCE AS Tom, in the gray of the breaking dawn, came pounding into the lines which surrounded the thousands of sleeping soldiers, he nearly precipitated himself upon the out-thrust bayonet of a sentry whose call of halt he did not hear. His breath coming and going in quick, sharp gasps, Tom managed to give the countersign, adding, “Sergeant Walton, Company C.” The sentry lowered his rifle and Tom proceeded; but a few yards further on he was compelled to repeat the process. For once he wished that all sentries were asleep on their posts. At brigade headquarters he encountered a man who refused to get excited, and who demanded to know in detail what it was Tom wanted before he would waken his own sergeant to see if the message could be delivered to the general.