Rangers Gabriel "Gabe" Walker and Jessie Deighan are dispatched to rescue their friend Hal Tucker and his girlfriend Sarah after Hal suffered a knee injury and stranded them on a peak in the Colorado Rockies. As they try to rescue Sarah, part of her harness breaks, and though Gabe is able to grab her, her gloved hand slips out, and she falls to her death. Hal blames Gabe for her death and Gabe is overcome with guilt, taking an extended leave.