When the annual Iditarod sled dog race in Alaska is hit by a series of late-winter storms, bush pilot Ben Helm gambles on a break in the weather to fly two dropped dogs and two race personnel to the checkpoint at Unalakleet. But the conditions worsen, and a catastrophic accident mid-flight forces Ben to ditch on the landfast sea ice somewhere on the Bering Sea.

Stranded, with no communications and only limited supplies, the three survivors, with their two canine companions, must try to ride out the storms and stay alive long enough for a rescue party to find them. Katja, a young, sick trainee vet from Norway, and Obie, an optimistic, middle-aged race judge, come to rely on Ben's survival grit and knowhow. Despite a personal childhood tragedy, he's never forgotten the vital lessons his mother taught him.

But the frozen wild is an unforgiving place. A series of fateful events, encounters and opportunities forces the survivors to repeatedly take all-or-nothing risks to reach civilization. A lost musher and her team provide much-needed dog power, but no bearings. Meanwhile, a lone hunter who comes to their aid might not be who he says he is. And with seemingly no end to the tundra, the wild horizon dares man and dog alike to dig deep in order to survive the trek of their lives.