Set in the mountains of Kipley County, Wyoming, the novel interweaves three timelines: a young woman's present-day fight for survival after a plane crash, the final days of a legendary 19th-century gunslinger as rendered in an unpublished manuscript, and a small-town historian's confrontation with uncomfortable truths about the hero he reveres.
In August 2024, Nina Terzić, a 24-year-old nanny and art history graduate student from Queens, New York, plunges into a remote mountain lake after falling from a small Cessna airplane. She and her boyfriend, Ben Robbins, an aspiring writer, had left their van with Ben's friend Jones and flown toward the town of Moraine, Wyoming, for dinner. A bird struck the engine, and Ben pushed Nina out before attempting an emergency water landing. Nina barely knows how to swim but drags herself to a fog-shrouded beach with meager supplies: a cracked phone with no signal, a penlight, trail mix, and 10 protein bars. She reasons that Ben swam to a different shore and that Jones will raise the alarm.
Throughout her ordeal, Nina calms herself using a technique rooted in her upbringing. Her mother, Ajda, a Bosnian immigrant, told her people are born with a finite number of heartbeats. Their downstairs neighbor, Mrs. Tima, a healer, once accidentally revealed something about Nina's death during a coffee reading. Though a doctor later dismissed the heartbeat theory, Nina has spent her life slowing her pulse by imagining herself as a deep-diving animal pressing into crushing depths. This ritual becomes her primary survival mechanism.
On Day 2, Nina hikes over a palisade and discovers an abandoned ghost town: a dozen buildings along a dirt track. On the far beach she finds a chunk of the Cessna's fuselage but no sign of Ben. She accepts he is likely dead and begins confronting her isolation, rationing food and exploring buildings. She sleeps in a stable with dried wildflower bouquets piled against its exterior.
Nina's bond with her employer, Violet Devander, emerges through memory. Nina was hired as a night nurse after Violet nearly died from a hemorrhage during childbirth and had an out-of-body experience in which she saw a silent figure in the delivery room. Nina recognized the figure as Death but kept quiet while Violet spent months visiting psychics. Eventually Nina brought Violet to Mrs. Tima, who told her bluntly that the figure was Death, that it was not her time, and that she was free. After initial anger, Violet broke down with relief, and Nina calmed her with the deep-breathing technique. This cemented their bond.
On Day 4, Violet's two-year-old daughter, Belice, accidentally calls from Violet's phone. Nina shouts "plane crash" into the terrible connection, but the call drops. Later, while searching for signal, she encounters a bear. Her phone pings with incoming messages, startling the bear, but the battery dies, and Nina hurls the phone into the bushes. Back in the stable, she discovers a trapdoor in the floor. In the crawl space she finds a canvas satchel, a coat labeled "PROPERTY OF LT HAWLEY," and a female corpse. She flees but later returns to examine the satchel, which contains a binder holding a photocopied dime novel and a typed manuscript titled "Sunrise" by LT Hawley.
The manuscript follows Anton Vargas, a 45-year-old former gunslinger who is terminally ill, returning to the mining town of Sunrise in 1902 after a 20-year absence. He carries an unread letter and seeks his old companion Doctor Thomas Maclean, known as Preacher. Fred Kipley, now deputy marshal, refuses to reveal Preacher's location and instead recruits Vargas to search for Jules Abadie, a missing boy. An extended flashback recounts how Preacher saved Vargas's life on the frontier, and how the two men, together with Kipley and a captive woman named Sadie Wilkins, fought off bandits at the besieged Greyrock station house. They became the Greyrock Four, frontier celebrities immortalized in dime novels.
The novel's third timeline shifts to 2003 and centers on Colin Yard, known as Coll, a young man in his early twenties in Salt Draw, Wyoming. Coll organizes the annual Greyrock reenactment on his grandfather's land, where the ghost town of Sunrise sits. One night at a local bar, a hunter named Bob Fournier arrives drunk with the dismembered remains of a wolf. Cornered, Coll grabs a severed paw and sings into it to defuse the confrontation. Bob later dies in the hospital; authorities warn that anyone who touched the wolf risks rabies or canine wasting disease. A writer named Louise Hawley arrives from Denver carrying the same olive-green satchel Nina finds under the stable floor. Louise has an unarchived 1936 recording of Kipley, in which the elderly Kipley describes Vargas as someone who "looked out for himself. Always" (196) and implies a romantic relationship between Vargas and Preacher. Coll grows defensive, insisting the community's version of history should not be disrupted.
LT Hawley's manuscript reaches its climax when Vargas tracks Jules to a dugout in the badlands and is shot from behind by Preacher himself, now missing an arm and an eye from a raid he carried out alone 20 years earlier after Vargas abandoned him. Preacher sends Jules to fetch his medicine bag, promising to escort the boy to safety the next night. Vargas reveals his cancer and offers Preacher the chance to kill him. Preacher refuses. The manuscript flashes back to their love affair: after a bitter argument, their confrontation collapsed into a kiss and a week of intimacy. Preacher then asked Vargas to help dynamite a reoccupied army fort. Vargas agreed but fled at dawn, and Preacher attempted the raid alone and was maimed. In the present of the story, Preacher takes the unread letter from Vargas's coat, and the manuscript breaks off. LT Hawley's personal notes follow, urging herself to finish and asking, "When's the last time anybody in your life actually saw you?" (262).
On Day 6, Nina matches LT Hawley's map to her surroundings and realizes the ghost town is Sunrise. Hemot City lies 25 miles north. Unable to leave LT Hawley's remains behind, she retrieves the skull from the crawl space and packs it in her backpack. She sets off but loses a day chasing what turns out to be a lightning-struck tree, not a campfire, injuring her knee along the way.
On Day 8, she watches a wolf pack kill a bull elk. Once the wolves scatter, she descends screaming, grabs raw meat from the carcass, and scrambles back up the ridge to find a truck on the road. Its driver, a man with severe facial scarring, offers her a sandwich and drives her toward the hospital. On the road they encounter Ben, alive. He climbs in and tells the driver they just got engaged. Nina recoils silently into the back seat. The driver introduces himself as Colin Yard. Nina, sitting on dried wildflower bundles, connects the pieces: the flowers match those outside the Sunrise stable, and the name matches LT Hawley's correspondent.
Coll warns that wolves in the area carry canine wasting disease and gestures to his own scarred face. Nina's heart suddenly stops. Ben performs CPR while Coll tells him she is gone. Inside the darkness, Nina feels isolated heartbeats pulsing through her, warm and enormous. When both men step away, a single heartbeat booms through her and she sits up. Shaken by Ben's behavior before the crash, when he ordered her out of their van on a Nebraska highway during an argument, and unsettled by Coll's connection to the remains she has been carrying, Nina runs to the truck and floors the gas pedal. She hurtles down the canyon road, LT Hawley's skull beside her, past a fenced-in obelisk under cottonwood trees, the roadside grave of Anton Vargas, and turns onto the highway into the open distance.