The fire was a success. he was safe. he remembered the advice of the old-timer on sulphur creek, and smiled. the old-timer had been very serious in laying down the law that no man must travel alone in the klondike after fifty below. well, here he was; he had had the accident; he was alone; and he had saved himself. those old-timers were rather womanish, some of them, he thought. all a man had to do was to keep his head, and he was all right. any man who was a man could travel alone. there was the fire, snapping and crackling and promising life with every dancing flame. he started to untie his moccasins. they were coated with ice; the thick german socks were like sheaths of iron half-way to the knees; and the moccasin strings were like rods of steel all twisted and knotted as by some conflagration. for a moment he tugged with his numbed fingers, then, realizing the folly of it, he drew his sheath-knife. but before he could cut the strings, it happened. it was his own fault or, rather, his mistake. he should not have built the fire under the spruce tree. he should have built it in the open. but it had been easier to pull the twigs from the brush and drop them directly on the fire. now the tree under which he had done this carried a weight of snow on its boughs. no wind had blown for weeks, and each bough was fully freighted. each time he had pulled a twig he had communicated a slight agitation to the tree--an imperceptible agitation, so far as he was concerned, but an agitation sufficient to bring about the disaster. high up in the tree one bough capsized its load of snow. this fell on the boughs beneath, capsizing them. this process continued, spreading out and involving the whole tree. it grew like an avalanche, and it descended without warning upon the man and the fire, and the fire was blotted out! where it had burned was a mantle of fresh and disordered snow. what is the theme of  this story?