Plot
One year prior, in Portland, Oregon, Jillian "Jill" Conway was kidnapped by a brutal serial killer who held her captive in a mass grave of his victims. After escaping and reporting the incident to the police, they failed to find the grave. They discovered that Jill had previously been committed to a psychiatric institution following her parents' death. They believed that her kidnapping was a delusion, and they reinstitutionalized her.
In the present, Jill, who lives with her sister Molly, works as a waitress at a local diner and regularly returns to the forest in search of the grave. While at work, she and her coworker are generously tipped by a regular customer. After returning home, Jill discovers that Molly is missing and is convinced her captor has taken her. She attempts to report to the police, who refuse to believe her except for Hood, the department's newest homicide detective.
Jill discovers that a locksmith company van was parked in front of her house overnight and speaks to the owner's son, Nick. She discovers a hardware store receipt containing items used for her own abduction. She holds Nick at gunpoint, and he reveals that a stranger named "Digger" rented the van. She goes to the hardware store and learns Digger's vehicle and address, but finds the police searching her car in response to a call about Jill waving a handgun inside the hardware store. Jill retreats into a bathroom and evades capture.
Digger's address leads Jill to the Royal Hotel, and she learns that Digger's real name is Jim LaPointe. She enters his vacated room and finds duct tape, pet food, and matches from her work. Jill returns a call from her psychiatrist, whom the police have contacted, who asserts that Jill is deluded. Jill visits her coworker, Sharon, who confirms that LaPointe is the regular customer and gets his phone number. Jill calls him, and he offers to meet her. However, she receives a call from her boyfriend Billy, who claims that Molly is sleeping at a friend's house after a night of drinking.
Jill again rightly discerns that this is another attempt by police to trick her into ending her search. She tells Billy she is on her way to meet with the abductor. Powers, upon learning that Jill's intends to meet with the alleged abductor at an unknown location, calls Jill to make another manipulative attempt to convince her to alter her plans, but that futile effort is interrupted by a call from LaPointe, who provides Jill with further directions to his location, a remote spot in Forest Park.
While she drives they continue conversing. LaPointe claims that he is not holding Molly. He describes in detail how a father and daughter formerly lived happily for many years together in a cave in Forest Park, a "magical place". He states he was surprised that the police search for the hole in which Jill said she was held was ended after only a week, given that the father and daughter lived in the 5000-acre park for many years without detection. He asks her to recount how she escaped from the hole. "You're a brave girl", he says, "driving out in the middle of the night to meet a man you hardly know". Jill eventually loses cellphone signal service. She must walk the final distance to LaPointe's campsite, where she finds and pockets pictures of LaPointe's prior victims.
Meanwhile, Molly breaks out of her restraints and emerges from under Jill's house. Molly tells Billy that she was hit by an assailant and dragged under the house. Powers and Lonsdale are shocked when they hear Molly's story, which confirms Jill's belief that her sister was abducted.
Jill finds the lantern-lit hole where LaPointe held her captive. LaPointe ambushes Jill and pulls her into the hole, intending to kill her with the same piece of bone that she stabbed him with before her initial escape. However, Jill shoots him and starts climbing up the rope ladder. When LaPointe grabs her and attempts to pull her back down, Jill desperately kicks LaPointe to break his hold and shoots him again. She then manages to climb out and extract the rope ladder, trapping LaPointe in the hole. After shooting LaPointe a third time in the leg when he does not tell her where Molly is, Jill demands that he tell her, promising to not shoot him again if he does. LaPointe tells her that Molly has been under Jill's house the whole time (evidently so that Jill would be lured into returning to the park to rescue Molly). Jill keeps her promise to not shoot him again, but instead pours a can of kerosene into the hole. As LaPointe begs for his life–"you said you wouldn't kill me"–Jill simply responds, "I lied". She then throws the lantern in the hole, burning LaPointe to death.
As Jill drives out of the park, she sees that Powers has texted: "Molly Safe. Come Home." Jill throws the handgun out of the vehicle window. Returning home, she finds Molly terrified but unharmed, with police officers and Billy present. As the sisters reunite, Molly expresses fear that LaPointe will return, but Jill assures her "we're fine, we're gonna be safe", then whispers further assurance (probably that LaPointe is dead) to Molly. When Powers asks about the man Jill went to meet, she says there was nobody there, sarcastically telling Powers, Lonsdale, and Hood, "It was all in my head."
Sometime later, Bozeman receives an anonymous package containing pictures LaPointe had taken of each of his victims bound and gagged, including Jill herself, and a map that indicates the spot in Forest Park where the police can find the hole. Realizing how wrong he was about Jill, Bozeman calls Powers into his office to investigate the new leads.
