When two brothers set off on a hike into one of Utah's most rugged canyons, they expect the trek will take no more than eight hours. But freezing conditions and extreme terrain push the brothers' limits, until a simple mistake turns a day of bonding into a disaster. With his leg shattered one brother cannot continue, and the other has no option but to go on alone and try to get help. One is left to battle against pain, freezing conditions and time. The other puts his life on the line, descending a dark and deadly canyon alone, with only one thought: If he fails, his brother will die.