Descent

The Courtland family arrives in the Colorado Rocky Mountains for a summer vacation before eighteen-year-old Caitlin, an undefeated high school track star, leaves for college on a running scholarship. Her fifteen-year-old brother, Sean, their contractor father, Grant, and their mother, Angela, settle into a resort motel at over nine thousand feet. Caitlin rouses Sean before dawn for a training run; he follows on a rented mountain bike as she pushes higher on unmarked roads. They discover a secluded shrine: a life-sized Virgin Mary statue with two broken fingers, old gravestones, and a bronze plaque promising "Forty Days of Grace," spiritual remission for those who pray there. Sean confides that he suspects their father of having an affair; Caitlin reveals that Grant once left the family for months when Sean was too young to remember. Back at the motel, Angela inadvertently picks up Grant's phone instead of her own, and a woman calls and hangs up, rekindling old suspicions about his faithfulness. Before the confrontation can develop, the phone rings again: Sheriff Joe Kinney informs them that Sean has been found injured on the mountain with a badly broken knee, but Caitlin is not with him.

The narrative shifts back to reveal what happened. As Caitlin and Sean climbed an unmarked road, a vehicle burst from the trees and struck Sean and his bike, sending him into a tree. The driver, a man in a pressed khaki shirt and yellow sunglasses, approached. With no cell reception, Caitlin faced a terrible choice: stay with her injured brother or ride with the stranger to get help. She tucked Sean's phone into his hand, promised to return, and got into the man's vehicle. As they descended and her signal returned, she called her father but reached only voicemail. She managed one word, "Daddy," before the man struck her.

The narrative jumps forward roughly a year. Grant lives alone in a small ranch house on the property of Emmet Kinney, the sheriff's elderly father, in the Colorado foothills. He performs ranch chores while obsessively scanning the mountains for Caitlin. Angela and Sean have returned to Wisconsin, where Angela lives with her younger sister Grace's family. Haunted by the earlier loss of her twin sister, Faith, who drowned when both girls were sixteen, Angela is emotionally fragile and on medication. Sean, now sixteen, navigates his recovery with a steel brace on his knee, carrying both the physical damage and the psychological weight of what he witnessed. He also bears the unspoken burden of his mother's blame for not stopping Caitlin from getting into the stranger's vehicle.

Grant and Emmet develop a quiet companionship on the ranch. Emmet's younger son, Billy, a reckless young man with a criminal history who drives a black El Camino, returns home intermittently and provokes conflict. One night Billy throws a party on Emmet's porch and forces his elderly father back inside. Grant retrieves Emmet's shotgun and shoots out a truck tire to drive the group away. Grant also forms a cautious friendship with Maria Valente, a waitress in town whose teenage daughter, Carmen, helps with Emmet's horses.

Sean, now seventeen, leaves Wisconsin without permission, driving Grant's blue Chevy across the Southwest. He learns his mother has been hospitalized after an apparent accidental overdose. In Omaha, he discovers college boys assaulting an unconscious girl behind a bar and attacks them. A hitchhiker he picked up earlier arrives with a gun and stops the assault, but Sean is arrested after being found driving the girl to the hospital. The lead attacker eventually confesses, and Sean is released to his father, who has driven from Colorado.

The novel provides extended glimpses into Caitlin's captivity. She is held in a small shack high in the mountains, chained to a bolt plate in the floor by her ankle. Her captor, whom she calls "the Monkey," carries a pistol loaded with only one bullet at a time. She secretly works to corrode the ringbolt securing her chain, feeding it water, sweat, and acidic liquids to promote rust. On Christmas Day, the Monkey takes her outside on snowshoes. She attempts to escape, descending with athletic precision, but the Monkey pursues and catches her. Later, a lone hiker discovers the shack. The Monkey returns, pretends to be a passerby, and shoots the hiker dead. Caitlin understands that no one who comes alone can save her.

Grant and Sean reunite and return to the ranch. Carmen and Sean ride horses into the mountains, but on the ride back Billy blocks the trail and breaks Sean's nose and wrist. That night, Grant enters Billy's bedroom carrying the shotgun. He tells Billy that what sustains him is not belief or hope but "disbelief," the refusal to accept a world in which his daughter can be taken without consequence. He warns that the next person who hurts anyone he loves will be the "one bad man" he has demanded of God. Emmet overhears and tells Billy to leave. Soon after, Emmet dies peacefully in his sleep. A body found on a mountain ledge turns out to be a college student named Kelly Ann Baird, not Caitlin, suggesting the abductor has likely taken other victims.

The turning point arrives when Billy, drinking in a Denver bar, sits next to a man who calls himself "Joe." Billy notices telling details: mud-caked boots, a nondescript black Bronco, and among the groceries in its cargo area, a box of tampons. He follows the Bronco into the mountains, texting road names to Sheriff Kinney. His final text is a single word: "blanket," referencing a withheld detail about the man's blanket that smelled of wool and gasoline. Billy follows the tire tracks on foot through deep snow and finds the shack by its faint firelight. Caitlin identifies herself through the door. He begins chopping through the thick wood with an ax, but the Monkey, who tracked him up the mountain, shoots him in the back. The Monkey drags Billy to a deep pit where he has disposed of other bodies, but as he positions Billy over the edge, Billy drives the man's own bowie knife into his neck. The Monkey tries to fire his pistol but finds it empty. He collapses.

Billy staggers back and finishes chopping through the door. He gives Caitlin his car keys and tells her to follow his tracks down, then dies in the doorway. Caitlin tries to break the chain but cannot. In an act later described by her surgeon as a near-textbook Syme's amputation, a disarticulation of the foot at the ankle joint, she severs her own right foot and cauterizes the wound against the hot stove. She fits her old running shoes over both the remaining foot and the bandaged stump, straps a belt below her knee as a tourniquet, and begins descending.

Sheriff Kinney and his deputy follow Billy's texts up the mountain. Kinney encounters a skeletal figure stumbling through the woods in Billy's oversized leather jacket. It is Caitlin. He lifts her and carries her down to his cruiser. The dogs later find the Monkey dead with the knife in his neck, and at least two other bodies in the pit.

Grant and Sean drive through the night to the hospital, and Grant calls Angela once he has seen Caitlin. A doctor privately discloses that Caitlin was pregnant during captivity but miscarried. At a Denver clinic, Dr. Wieland, a podiatric surgeon, praises the precision of Caitlin's self-amputation and says that with a carbon running prosthetic, she will run again. Grant weeps when shown the only things she brought down from the mountain: her old running shoes.

Angela flies from Wisconsin and embraces her daughter for the first time in nearly three years. Billy's funeral is held beside his father Emmet's fresh grave. Before leaving Colorado, Caitlin and Sean return to the mountain shrine. Sean confesses he saw the man's eyes when the vehicle struck him but could never bring himself to tell her. She asks if they will still give her the track scholarship. "Maybe half," Sean says, and she laughs. He carries her back to the car. The four Courtlands drive east together for the first time since that July morning, the road stretching flat and bare across the plains, hiding nothing.