Dave Metz sets out with his two dogs and a backpack full of food to march across trackless terrain of immense proportions. His dogs are large ninety-pound Airedale terriers, full of life. But one is freshly recovered from an injury that Metz fears is the heralding of something more-cancer. The other, feisty tough and without any fear, attacks a porcupine and suffers from infection on the remotest leg of the trek. The goal of the journey then switches from his zealous ambition of crossing Alaska on foot to getting out of the wilderness and saving his dog at all cost. There are weeks of isolation, grizzly bear encounters, wild rivers to wade, mountain ranges to cross, swarms of mosquitoes, gnawing hunger, and weariness from marching day after day. Near the end of his trek, with dangers escalating, he builds a log raft to float one hundred miles down the Sheenjek River to civilization. He encounters raging forest fires along the way, almost drowns, and all the while his preconditioned drive to stay alive is a vivid reminder of his traumatic birth.