When adrenaline junkie Aaron Ralston sets off to conquer a canyon in the stunning landscape of a Utah national park, he has no idea quite how bad a day he's in for. When he gets his arm stuck under a rock, he's on his own. During the 127 hours he's pinned to the canyon wall, Ralston weighs his options, and, finally, summons the sheer grit and force of will needed to commit the act that could give him a slim chance of survival.