“That’s queer!” murmured Andy, somewhat disturbed. “Give him another call, boys, as loud as you can.” They did so willingly, and Boxy added his imitation locomotive whistle as well. It brought forth no reply. Jack was lost to them. What could have become of him? CHAPTER XIII. JACK’S EXPERIENCE. When Jack left the other members of the Zero Club to look for a suitable camping-place for the night, he had no intention of walking any great distance away. He struck down the lake shore, in a direction directly opposite to that taken by Harry, and at almost right angles to that pursued by the others. Jack walked probably fifty yards before coming to anything but a flat surface of snow and ice, with here and there a tree or a bush. “This is no good,” he murmured to himself. “I’ve a good mind to go back and try in the other direction.” Had he done so, he might have saved himself all the trouble that followed, and likewise saved the others from a deal of anxiety concerning his welfare. But Jack remembered that Harry had gone off in the opposite direction, and so he kept on until he reached a small rise of ground, beyond which was a dense thicket of great trees, some all of a hundred feet in height. “There ought to be a first-rate place among those trees,” he thought. “I’ll investigate a bit and see.” Jack walked in among the trees and soon located a spot between several tall maples that he thought would be just the thing. Five trees were in a semi-circle, and he calculated that by heaping the brush around them a temporary shelter that would be both safe and warm would be secured. He walked around the trees, and then to a spot a few yards away, where brush grew thickly. Here both the snow and the leaves were thick, and without warning he suddenly found himself sinking down in the midst of both. He tried to scramble to a place of safety, but it was too late and down he went into an opening that was all of ten feet deep. The leaves and snow tumbled with him, and he was all but smothered. When at last he managed to get his head clear of what was around him, he found himself up to his armpits in the mass, and almost powerless to move the lower portion of his body. Jack was not one to cry for help, so, for a while, he remained silent, doing his best to extricate himself from his difficulty. It was very cold down at the bottom of the hole, and, despite his exertions, he found himself gradually getting chilled to the bone. It was also dark, and this made his situation worse than had it been daylight. At last, in desperation, he wrenched himself away from the snow and rubbish, and freed himself as far as the waist. But higher than this he could not get, for every time he attempted it he only slipped back again. A half-hour was passed in trying to extricate himself, and by that time he was so worn out he was unable to make further effort.