Soon enough, however, Heimo's worst fears were realized. By late September, a foot of snow had already fallen, and it kept coming, meaning that he was almost always breaking trail. And the temperature was tumbling. First 5 below, then 10 below. On October 1, Heimo woke up early, shivering in his sleeping bag, covered in a thin layer of frost. The sky was slate blue, and wind was barreling out of the north. Reluctantly, Heimo crawled out of his bag and walked over to the cabin where he had nailed a thermometer to a large white spruce. It read 15 below, and now Heimo knew for certain that he was in trouble. Resisting the temptation to panic required all the fortitude Heimo had. He slipped on his parka, canvas mukluks, wool gloves, hat, pants, and a backpack, in which he'd packed macaroni and bread enough to last him three days, and then set off upriver, determined not to return until he'd killed a black bear or a moose.