Dusk was not far off, and there was no time to be lost, and without further parley or useless waste of breath and strength Bobby set bravely to work with his snow knife, as any wilderness dweller in similar case would have done, and in a little while had prepared for himself a grave-shaped cavern in the drift, with a stout roof of snow blocks, and when it was finished he crawled in and closed the entrance with a huge block.