The novel opens in November 1976 in rural Klickitat County, Washington, where newly hired deputy sheriff Buzz Almond responds to a missing-person call. Earl Kanasket, an elder of the Klickitat tribe, reports that his 17-year-old daughter, Kimi Kanasket, never came home from her shift at the Columbia Diner. Kimi is a responsible student with a scholarship to the University of Washington. Her older brother, Élan, reveals she recently broke up with her boyfriend, Tommy Moore, a Golden Gloves boxer. Earl notes that tribal protests against Stoneridge High School's use of the name "Red Raiders" and a Native American mascot have created tension in the community. Buzz and Earl retrace Kimi's walking route as snow begins to fall but find no trace of her. Kimi's body is later found in the White Salmon River, and the official ruling is suicide. Buzz investigates on his own, discovering tire tracks and shoe impressions in a remote clearing in the woods, but the detective assigned to the case dismisses the evidence with a racist remark about Native Americans, shutting Buzz out.
Forty years later, Seattle homicide detective Tracy Crosswhite and her partner, Kinsington "Kins" Rowe, catch a domestic shooting case. Angela Collins has confessed to shooting her estranged husband, Tim Collins, in the back. Angela's father, defense attorney Atticus Berkshire, instructs Angela and her teenage son, Connor Collins, to remain silent. The investigation reveals a 21-minute gap between the gunshot and the 911 call and physical evidence contradicting Angela's self-defense claim. When Connor, newly turned 18, walks in alone and confesses that he shot his father, the competing accounts create reasonable doubt against either suspect.
Tracy and her boyfriend, Dan O'Leary, travel to Stoneridge for the funeral of Buzz Almond, who died of colon cancer. Buzz's daughter Jenny Almond, now the Klickitat County sheriff, shows Tracy a thick case file on Kimi that Buzz kept hidden in his desk for decades, apparently continuing to investigate on his own. Jenny believes her father never accepted the suicide ruling and asks Tracy for an independent review.
Tracy's review of the file reveals newspaper articles about the Stoneridge football championship played the same weekend Kimi vanished, a coroner's report, photographs of Moore's damaged truck, and two unexplained cash receipts from auto businesses owned by the Devoe family. She sends the evidence to forensic anthropologist Kelly Rosa and crime-scene analyst Kaylee Wright. Rosa determines that Kimi's injuries, including a fractured pelvis, bilateral rib fractures, and a cracked sternum, are consistent with being struck by a vehicle, not with impacts from river rocks at the low flow rate that week. Rosa identifies tire-tread bruising on Kimi's back and concludes Kimi could not have walked to the river and could have survived with timely medical attention. Wright's analysis reveals that a truck went airborne off a hilltop and crashed into the clearing where Kimi lay, that three to five people were present based on different shoe impressions, and that someone wearing rare rubber hunting boots carried Kimi's body to a vehicle.
Tracy travels to the Yakama Reservation, where Earl, now in his eighties and using a wheelchair, gives her his blessing to investigate. Tracy interviews Moore, now sober for 20 years, who denies killing Kimi and says the guilt of believing she died because of him nearly destroyed his life.
Tracy's investigation shifts to the Four Ironmen, the celebrated players of that 1976 championship team: quarterback Eric Reynolds, center Hastey Devoe, running back Archibald Coe, and fullback Darren Gallentine. She learns from retired newspaper publisher Sam Goldman that Eric built a successful construction company, Hastey drank his way out of college and now works for Eric, Archibald had a mental health crisis in the Army and works at a nursery, and Darren died by suicide in 1999. A photograph of Eric's Ford Bronco shows oversize off-road tires matching the type found in the clearing. Tracy visits the clearing at night and discovers a freshly planted shrub in recently tilled soil. On a later visit, she finds dozens of dead plants in the surrounding woods, evidence of years of failed attempts to grow something in the spot, and traces the planting to Archibald at a nearby nursery.
Tracy confronts Archibald, who is emotionally fragile and cannot discuss what happened. Jenny's deputies arrest Hastey for DUI, and Tracy interrogates him, but he refuses to talk. The next morning, Archibald is found hanged in his hothouse in an apparent suicide, eliminating Tracy's best potential witness.
Tracy tracks down Darren's widow, Tiffany Martin, who reveals that Darren had escalating nightmares throughout their marriage, never mentioned the championship, and never returned to Stoneridge. Martin eventually releases Darren's therapy records, which contain his detailed account of that night: The four boys snuck out to drink. Eric, furious that a girl he had been seeing went out with Moore, taunted Kimi on the roadside. When she talked back, he chased her into the woods with the Bronco. The truck went airborne over a hill and landed on Kimi in the clearing. Eric convinced the terrified boys to stay silent. Darren's recurring nightmare was a suppressed memory of Kimi opening her eyes and begging for help. After recounting this in therapy, Darren went home and died by suicide.
Reexamining the evidence, Tracy realizes a fifth person returned to the clearing alone, wearing the hunting boots, and carried Kimi to the river. The cash receipts, the quick repair of the Bronco, and a second set of tire tracks point to Ron Reynolds, Eric's father and the football coach. Tracy confronts Eric, who is shattered to learn that Kimi was still alive when Ron threw her into the water. Eric confronts his father, who is unapologetic, insisting he did what he had to do to protect his son's future. Eric retrieves Ron's hunting boots from storage and delivers them to Tracy.
As Tracy follows Eric home so he can arrange his surrender, Lionel Devoe, the Stoneridge chief of police and Hastey's brother, ambushes them with Eric's handgun. Lionel plans to stage a murder-suicide to protect himself and Hastey from prosecution. Eric charges Lionel, who shoots Eric in the shoulder. Tracy retrieves her Glock and kills Lionel with two shots. Eric survives and Ron Reynolds is arrested.
Back in Seattle, Tracy resolves the Collins case. Since Berkshire has withdrawn as Angela's attorney, Tracy brings Angela in for questioning while Connor and Berkshire watch through one-way glass. Angela maintains that Connor shot Tim, but Connor breaks down and reveals the truth: Angela said she had to kill Tim to keep everything, shot him herself, then directed Connor to stage evidence of abuse and rehearse a false confession. Angela is charged with murder.
Eric pleads guilty to vehicular homicide. Ron refuses to plead and faces a second-degree murder charge. The stadium is renamed Kimi Kanasket Memorial Stadium at Eric's request. Tracy visits Earl, now in hospice care, and tells him Kimi did not take her own life. Earl opens his eyes, sheds a single tear, and dies peacefully. In the epilogue, Tracy and Dan plant shrubs in the clearing in memory of Earl, Darren, and Archibald, and discover that Archibald's last planting is finally flourishing. Tracy places the closing papers of the investigation at Buzz's grave, and Dan reveals he is moving closer to Seattle to be near Tracy, affirming their future together.