Backpacking in California's Laguna Mountains to repair their troubled ten-year relationship, Owen Underwood and Dwayne Bosco never imagined their four-day "therapeutic excursion" would turn into twelve days of terror. Stalked by a ferocious, unwavering mountain lion, they find refuge the only place they can—on the roof of a boarded-up miner's cabin. To stay alive they must keep the fierce, hungry predator from reaching them. As the hours stretch into days, hope for rescue fades. Dwindling provisions and exposure begin to eat away at their bodies and minds. Their new hell makes their carefree college days where they first met at a fraternity party seem light years away. With each escape plan falling apart, their only deliverance might come with death. Yet even as they face their demise, they wonder if they can find the love they once had for each other to at least utter a final good-bye.