That night the big white moon had around its edge a crimson rim. It meant cold--intense cold. Always the plague came in the days of greatest cold--the lower the temperature the more terrible its havoc. It grew steadily colder that night, and the increased chill penetrated to the heart of the windfall, and drew Kazan and Gray Wolf closer together. With dawn, which came at about eight o'clock, Kazan and his blind mate sallied forth into the day. It was fifty degrees below zero. About them the trees cracked with reports like pistol-shots. In the thickest spruce the partridges were humped into round balls of feathers. The snow-shoe rabbits had burrowed deep under the snow or to the heart of the heaviest windfalls. Kazan and Gray Wolf found few fresh trails, and after an hour of fruitless hunting they returned to their lair. Kazan, dog-like, had buried the half of a rabbit two or three days before, and they dug this out of the snow and ate the frozen flesh. All that day it grew colder--steadily colder. The night that followed was cloudless, with a white moon and brilliant stars. The temperature had fallen another ten degrees, and nothing was moving. Traps were never sprung on such nights, for even the furred things--the mink, and the ermine, and the lynx--lay snug in the holes and the nests they had found for themselves. An increasing hunger was not strong enough to drive Kazan and Gray Wolf from their windfall. The next day there was no break in the terrible cold, and toward noon Kazan set out on a hunt for meat, leaving Gray Wolf in the windfall. Being three-quarters dog, food was more necessary to Kazan than to his mate. Nature has fitted the wolf-breed for famine, and in ordinary temperature Gray Wolf could have lived for a fortnight without food. At sixty degrees below zero she could exist a week, perhaps ten days. Only thirty hours had passed sinee they had devoured the last of the frozen rabbit, and she was quite satisfied to remain in their snug retreat. But Kazan was hungry. He began to hunt in the face of the wind, traveling toward the burned plain. He nosed about every windfall that he came to, and investigated the thickets. A thin shot-like snow had fallen, and in this--from the windfall to the burn--he found but a single trail, and that was the trail of an ermine. Under a windfall he caught the warm scent of a rabbit, but the rabbit was as safe from him there as were the partridges in the trees, and after an hour of futile digging and gnawing he gave up his effort to reach it. For three hours he had hunted when he returned to Gray Wolf. He was exhausted. While Gray Wolf, with the instinct of the wild, had saved her own strength and energy, Kazan had been burning up his reserve forces, and was hungrier than ever.