The boys grasped the situation in an instant. The wind had turned to the south while they slept, and a flying spark had set fire to the canvas over their heads. The dry cloth was now flaming up brightly, while burning pieces were falling on the blankets. They jumped up, seized their caps, and fell to work with a will to help their father and uncle, who were beating away desperately at the blazing side and roof. It was quick, breathless work. Not only must they prevent the spread of the flames overhead, but they must also take care of the bedding and whatever clothing was in the hut. David, after extinguishing the fire immediately around him, dropped his cap and pulled both blankets and clothing in a heap out into the snow, where he spread them all out, carefully quenched the sparks, and then ran back to the hut, where the flames were presently brought under control. This was not accomplished, however, until nearly half the roof and all of one side were gone. The fire-fighters, panting and exhausted, gazed ruefully at the ruins. It was too dark now to ascertain the exact amount of the damage, but there could be no doubt it was very serious. No one, however, was disposed to cry over spilled milk; and Uncle Will, who had known many disasters of various sorts in the course of his rough experience, even laughed grimly and declared that what he regretted most was the singeing of his beard, of which he had lost fully two inches. Both men complimented the boys on their efficient work, which contributed to a large degree toward the saving of the contents of the hut, as well as that part of the hut itself which remained. "I believe Lucky and Coffee Jack slept through it all," said Mr. Bradford, peering through the darkness toward the beach, where the Indians had pitched their rude tent. As he spoke, there was a crackling and a flash of light behind the hut. Not three feet from the rear of the structure rose a tall dead spruce. Fire from the burning canvas had been communicated to a dry vine leading into a net-work of small branches at the foot of this tree, and a tiny flame, silent and unseen, had been stealthily creeping toward this mass of tinder. "Down with the hut, boys!" cried Uncle Will, instantly realizing the new danger. "Quick, before it gets too hot! Never mind the tree,--you can't put _that_ fire out!" This last was addressed to Roly, who had promptly attacked the burning branches with his cap, but only succeeded in tearing that article on the twigs without much effect on the flames. Knots were untied with nervous haste, and where they proved refractory they were cut. That part of the canvas nearest the tree was first folded over out of harm's way, and soon the whole was loosened and dragged to a distance, and none too soon. The fire ran up the dry twigs with startling rapidity and a roar that presently aroused those sound sleepers, Lucky and Coffee Jack, who came running up in surprise.