At the canyon entrance, Kelly and Egan tell Sondra and Allison that their children were buried; Allison suspects Kelly wanted to believe what he was saying rather than actually knowing it to be true. The two mothers wait at Sondra’s home after law enforcement confirms that Kalin and Landry disappeared into the rockfall.

In the study, Sondra tells Allison more about the Porch-Gatestone feud, which traces back roughly 150 years to an alleged theft of two horses and a mule. Her late husband, Dallin, was researching the 1849-1850 Battle Creek Massacre, in which Church militiamen, including ancestors Alfred Gatestone and Garrison Porch, hunted Timpanogos people through Isatch Canyon; Chief Pareyarts’s wife was reportedly driven off the peak now called “Squaw Peak.” Sondra reveals that Dallin died from a horse kick, likely from Ash, Tom’s horse. Sondra also shows Allison the manuscript Dallin was working on before he died, centering on the moment in Homer’s Iliad where the immortal horse Xanthos speaks to Achilles to prophesy his death. The manuscript ends on the word Grace.

The stake president of Sondra’s church, Havril Enos, calls and implies in careful language that Sondra’s association with Allison may be inappropriate; Sondra is troubled but undeterred. She invites Allison to church Sunday, and Allison accepts. Sondra then contacts pilot Tucker Wyatt to arrange a helicopter at dawn and, studying the topographic map, concludes that Tom’s knowledge of the mountains would have led Kalin toward Kirk’s Cirque and Altar Lake.

Meanwhile, Tom’s ghost leads Kalin and Landry through a hidden gap in the canyon’s cliffs, eventually reaching Kirk’s Cirque, where they set up camp. Kalin fails to start a fire; while he forages for wood, Landry uses flint, steel, and her diary’s covers as tinder and lights it herself. Over a small meal, they care for the horses’ injuries, and Kalin treats Navidad’s wounded pastern. Landry talks of wanting one day to write a memoir. Kalin admits his talent for guns, but reveals he swore off them after their use frightened even the horses away from him. Tom, growing increasingly distant and otherworldly, warns that he is becoming something other than himself and that time is running out.

Early Saturday, Old Porch wakes before dawn to find Egan already gone. He receives devastating news from Senator Hays: The bill will not come to a vote, ruining Old Porch’s Four Summits mountain resort plan. Standing in the rain afterward, he fights back nausea from both financial ruin and the surfacing memory of Russel’s death.

Egan, Kelly, and Billings return: The canyon is flooded and closed. Egan proposes an alternate approach via “Indian Hills” and “Squaw Peak” on ATVs. Hatch, who had scouted the route before dawn, confirms it is viable but recommends a midday departure.

Meanwhile, Billings visits Trent Riddle’s apartment to kill him and unexpectedly encounters Detective Peters, who is separately searching for Riddle. Billings agrees to give a statement at the police station and carefully manages his answers to avoid confirming that Riddle was sober, a discrepancy that arouses Peters’s suspicion.

Francis suggests the family visit Russel at the Erville Family Mortuary before the canyon reopens. At the mortuary, the Porches view Russel’s body in a ruby casket. Old Porch, consumed by calculations of financial catastrophe, touches Russel’s collar and briefly realizes his own culpability. He delivers a speech demanding Russel be avenged. The family affirms him, though Francis alone grieves without anger.

Kalin wakes at dawn to find the fire dead. After he revives it, he scouts and confirms the rockfall has made descent nearly impossible. He discovers a large rattlesnake coiled against Landry’s head. He grabs it barehanded and removes it, saving her life. She then confesses she ate all the remaining beans while Kalin was scouting, leaving him nothing.

Tom confirms Kalin’s fears: They are trapped, and the cirque’s only exit will bring them directly into the Porches’ path. Kalin refuses to retreat. He and Landry break camp and prepare the horses. The rain continues, however, making the planned route too slick to attempt.

They walk the horses to Altar Lake to graze. Tom narrates the history of Jojo’s bond with Landry: When Landry was adopted by the Gatestones as a six-year-old, she slipped into the paddock and embraced a famously dangerous stallion; the stallion went still for her and has been inseparable from her ever since.

When the rain pauses, a helicopter carrying Old Porch appears over the cirque. Kalin stands on a rock ledge and faces it alone. Old Porch makes a mocking gun gesture at Kalin; Kalin holds his gaze without moving. Both Old Porch and the pilot feel an inexplicable chill near the boy, forcing the helicopter to exit the cirque. Landry has the Colt ready when Kalin runs back; he tells her to put it away. Shortly after, Kalin experiences food poisoning from some jerky he ate. He burns the remainder of their supply, leaving them completely without food.