Jake Buckman, a financial planner in suburban Pennsylvania, has spent the past five years building his company, Gardenia Trust, at the expense of his relationship with his sixteen-year-old son, Ryan. His wife, Pam, a Superior Court judge, has become Ryan's primary parent. On a Friday night, at Pam's encouragement, Jake picks Ryan up from a movie theater, hoping to reconnect. The two share a rare moment of warmth on the drive home as Ryan opens up about a girl he wants to ask on a date. When Ryan asks to drive on Pike Road, a deserted shortcut, Jake agrees, wanting to keep the good feeling alive, even though Ryan only has a learner's permit and is prohibited by Pennsylvania law from driving after 11 p.m.
As Ryan steers around a blind curve, he glances at Jake during conversation, and the car strikes something. Jake discovers the victim is not a deer but a woman runner in dark clothing. He attempts to resuscitate her, but she is dead. Jake's first instinct is to call 911 and claim he was the driver, but Ryan then produces a bag of marijuana, confessing he smoked with a friend earlier that day. Jake realizes that if police test Ryan, they will find marijuana in his blood, potentially leading to charges of driving under the influence (DUI) and vehicular homicide, with up to 10 years in prison. Jake stuffs the phone and marijuana into his pocket and tells Ryan to get back in the car. They leave the scene without calling anyone.
At home, Jake hides his blood-stained parka and lies to Pam. The next morning, he hears a radio report identifying the victim as Kathleen Lindstrom, a sixteen-year-old junior at Ryan's own high school. To explain the damage to the Audi, Jake deliberately crashes it into a Dumpster at a convenience store. A police officer gives him a ride home and unwittingly describes the investigation's methods, noting there are no red-light cameras on Pike Road.
Ryan, devastated to learn the victim was a classmate, secretly emails a DUI lawyer named Morris Hubbard. Jake reluctantly accompanies Ryan to meet Hubbard, who explains that Jake would face charges for negligent entrustment, a legal doctrine holding a supervising adult criminally liable when an underage driver causes a fatality. Ryan blurts out that he was the driver, ruining Jake's planned cover story. Father and son reach a grim understanding: Turning themselves in would send them both to prison. Hubbard notes the statute of limitations for leaving the scene is seven years and implies the odds of detection may be low. Meanwhile, Pam announces she is the front-runner for a federal district court judgeship requiring extensive Federal Bureau of Investigation (FBI) background checks, adding another layer of danger. Jake burns the bloody parka and disposes of the ashes at an abandoned quarry.
At Ryan's next basketball game, a man calling himself Lewis Deaner sits beside Jake and makes pointed references to the hit-and-run and Jake's Audi. Jake investigates and discovers the name is fake. The man arrives at Jake's office the next morning with photos and video of Jake and Ryan at the accident scene, including a close-up of the Audi's license plate, and demands $250,000 wired to an offshore account. Jake arranges a line of credit, reasoning the new account will not appear on financial statements being disclosed to the FBI. The blackmailer escalates by sending Ryan menacing texts urging him to kill himself. Jake later discovers the man's real name is Andrew Voloshin, an employee at GreenTech, the same small IT company where Kathleen and her mother also worked. Jake confronts Voloshin, deducing that he had been stalking Kathleen along Pike Road and capitalized on her death rather than reporting what he witnessed.
After learning from Dr. Dave Tolliver, Ryan's volunteer shooting coach and a child psychologist, and from a friend's mother that Ryan has been smoking marijuana, Pam confronts Ryan. Under pressure, Ryan confesses that he killed Kathleen on Pike Road. Jake tells Pam everything. She is furious, withdraws from the judgeship, but ultimately declares the family will keep the secret. Ryan then reveals that during his sophomore year, he overheard Pam on the phone saying "I miss you, Dave. I love you" (213), exposing her affair with Dr. Dave. Jake walks out, drives aimlessly, briefly considers steering into oncoming traffic, but chooses to live.
The next morning, complications escalate. Jake's banker cannot complete the wire transfer on time. Two detectives arrive, revealing Voloshin has been murdered in his apartment. A brunette was seen leaving after a loud argument shortly before his death. Jake sticks to his cover story. Then Pam texts him: "Don't worry. I took care of Voloshin" (246). At the quarry, Pam explains she confronted Voloshin at his apartment, argued with him, and photographed his bulletin board of stalker photos before leaving him alive. Jake realizes Pam is the brunette the detectives described. Overwhelmed, Pam declares she wants a divorce.
Examining Pam's photos, Jake discovers hidden images of a woman getting into a dark BMW on Dolomite Road near Pike Road. At Kathleen's memorial service, he spots the matching car in the parking lot. Jake goes to Dr. Dave's house to confront him about the affair with Pam, and when a motion-detector light illuminates the garage, Jake sees the same BMW. He realizes Dr. Dave was in a secret relationship with Kathleen, his own teenage patient, and killed both her and Voloshin. Dr. Dave pulls a gun and shoots Jake in the stomach. As Jake bleeds on the floor, Dr. Dave explains his plan to frame Jake for Voloshin's murder by planting the stolen laptop and phone in Jake's car trunk. As Jake fades from blood loss, Pam, unable to reach him by phone and growing alarmed, arrives with Ryan. Ryan tackles Dr. Dave, and during the struggle, the gun discharges, wounding Dr. Dave. Jake whispers "trunk" (320) before losing consciousness.
Jake wakes in the hospital. Pam tells him they gave the police full statements and turned over the laptop and phone. Detective Zwerling reveals the critical finding: Kathleen was already dead when Jake and Ryan hit her. Dr. Dave had killed Kathleen by slamming her head into the BMW's dashboard when she threatened to expose their relationship after he tried to end it, then left her body on Pike Road to make the death look like a hit-and-run. Jake and Ryan struck her body within minutes of her actual death. Dr. Dave is charged with both murders. Jake and Ryan face only misdemeanors for leaving the scene, with fines but no prison time. Ryan's charges are handled in the juvenile system, resulting in probation and community service. Pam steps down from the bench for her role in the cover-up, though she faces no criminal charges.
Six months later, Dr. Dave has pleaded guilty and received life without parole. Jake's company survived, and Pam works as a contract lawyer while they attend marriage counseling. Ryan lost his basketball recruiting prospects but found purpose as an assistant coach for a youth team and is going on his first date. The family planted a weeping willow in their backyard as a private memorial to Kathleen.