Best friends Becky and Hunter are adrenaline junkies. Becky suffers a great loss when her husband Dan falls to his death while rock-climbing.

51 weeks after Dan’s death, Becky is a depressed alcoholic who has distanced herself from her father, James, because he suggested that Dan was not as good a guy as Becky had made him out to be. In desperation to support Becky, Hunter invites her to climb a 2,000 foot (610 m) TV tower in the desert. Though Becky is hesitant, she changes her mind and decides not to live in fear.

The girls make it to the top of the tower, where they spread Dan’s ashes. However the ladder to climb down breaks off, leaving them stranded at the top. Although they have two smartphones with them, neither has a signal up there. In the air, Becky and Hunter combat dehydration, starvation and vultures while trying to reach out for help, but Hunter’s phone breaks when they try to send a message while a couple of rednecks who see them steal their car rather than help.

Hunter tearfully admits to having had an affair with Dan before he married Becky, which contributed to distancing herself from her after his death. Hunter climbs down and reaches their bag with water and a 4K drone that landed on a communications dish. Becky tries to use the drone to deliver a piece of paper with a message asking for help to their motel. Unfortunately, the drone is destroyed by a passing mining truck in the last minute only a few yards before arriving at the motel.

Becky finally realizes that she had been hallucinating and that Hunter actually died after she fell from her harness, landed on the communications dish below and bled out. Becky had only managed to pull the bag up and, delirious from the lack of food and water, had hallucinated Hunter’s presence on the tower with her for some time. After killing a vulture that had attacked her and eating it for sustenance, Becky makes one last attempt to survive by climbing down to Hunter’s body and sending a message for help to James by stuffing her phone inside Hunter’s body for protection and then throwing the body off the tower so the phone could receive a signal at lower altitude once it crashed on the ground.

The plan works, the authorities find her, James shows up and Becky reconciles with him.