The story begins before the wolf-dog hybrid is born, with two men and their sled dog team on a journey to deliver the coffin of Lord Alfred to a remote town named Fort McGurry in the higher area of the Yukon Territory. The men, Bill and Henry, are stalked by a large pack of starving wolves over the course of several days. Finally, after all of their dogs and Bill have been eaten, four more teams find Henry trying to escape from the wolves; the wolf pack scatters when they hear the large group of people coming.

The story then follows the pack, which has been robbed of its last prey. When the pack finally brings down a moose, the famine is ended; they eventually split up, and the story now follows a she-wolf and her mate, One Eye. The she-wolf gives birth to a litter of five cubs by the Mackenzie River, and all but one die from hunger. One Eye is killed by a lynx while trying to rob her den for food for the she-wolf and her cub; his mate later discovers his remains near the lynx's den. The surviving cub and the she-wolf are left to fend for themselves. Shortly afterward, the she-wolf kills all the lynx's kittens to feed her cub, prompting the lynx to track her down, and a vicious fight breaks out. The she-wolf eventually kills the lynx but suffers severe injury; the lynx carcass is devoured over a period of seven days as the she-wolf recovers from her injuries.

A triangle romance provides the basis for a questioning of the meaning of masculinity, as well as an examination of agribusiness in California.

Jack London said of this novel: "It is all sex from start to finish -- in which no sexual adventure is actually achieved or comes within a million miles of being achieved, and in which, nevertheless, is all the guts of sex, coupled with strength."