Meanwhile Ollie had encountered even greater difficulties than Tom in his search for the commanding officer of the Engineers, for although he went directly to the wood, he found only small squads at work there, the main body having progressed in a circling movement to the northward of the town, to prepare the pathway for the day’s advance. When, after the greatest difficulty, he finally did locate the headquarters of the colonel, he arrived there just in time to see the latter and his aides departing at the head of a hundred men. Saluting a lieutenant, Ollie started to tell him his story, but was cut short with the information that the news already had been received and they were then on their way. “But you arrive at a good time,” the lieutenant added quickly, and addressing a superior he informed him that Ollie could take them directly to the spot. And thus it was not without a justifiable feeling of being of some real importance that Ollie was called to the colonel’s side, and walking beside that officer, to direct the way, was plied with questions as to the discovery. It was little enough that Ollie could tell, for Tom had given him but a bare outline of the danger that confronted the troops. Nevertheless the colonel thanked him warmly, not forgetting to add a word of praise for all three of the lads after he had been told how it happened that the mouth of the tunnel had been discovered. “And you got your man after all?” he asked, when Ollie had finished, having touched but lightly upon the fact that all three had at one time dropped off to sleep. “Yes, sir, he’s wounded,” the lad responded. “Well, he’ll probably wish he had been killed outright,” was the colonel’s cryptic comment. As if in reply to that remark, German guns far to the north let go a salvo of shells, several of which fell uncomfortably near. The colonel glanced in the direction from which the projectiles seemed to come, but his pace never wavered. “Fritz seems to be out of bed, anyway,” was all he said, as another shell exploded not a hundred yards to the left of them, throwing up a veritable geyser of dirt and rock and splinters of steel. As they came over a little knoll, Ollie pointed out where the tunnel entrance was, and the colonel raised his glasses to get a better view as he walked. Approaching, from an about equal distance beyond the spot where Harper and his prisoner sat, were the general and members of his staff. It was when both parties were within fifty feet of the entrance to the passageway that a shell exploded with such violence and in such proximity that it knocked both Harper and his prisoner on their backs. For a moment everyone thought they had been killed. It was Ollie, who with a feeling of dread, realized the real damage that that shell might have done; and as misfortune would have it his surmise was right. It had landed directly over the tunnel, a few yards beyond its entrance, and with such force as to cave the whole thing in!