Octane

Two people posing as paramedics render aid to an overturned car on the freeway. The woman tapes the injured man’s mouth shut and pulls him from the wreck, then speeds away as an ambulance arrives, signaling the start of a predatory operation. The scene hints at a coordinated abduction network operating nearby.

Senga and Nat are on a six-hour overnight drive home when they pass the crash and notice a man and woman taking photographs of the scene. The man notably turns the camera toward Senga, branding her as a potential target. The encounter plants early unease about who is watching them.

The pair stops at a truck-stop diner to rest. Nat befriends a young female backpacker and offers her a ride, while Senga remains unsettled by the backpacker and the odd ambient CD she plays in the car.

The backpacker is dropped at a picnic area after leaving behind a CD. Seconds later, she seems to have vanished, heightening the sense that something sinister is at work. The incident unsettles Senga and Nat.

Tension over Nat's birthday plans leads to an argument with Marek, Nat's father. Nat ultimately climbs into an RV with the backpacker and a strange couple, separating from her mother. The decision pushes Senga toward a desperate pursuit.

Senga seeks aid from a police officer, then tails the RV in a bid to locate Nat. She breaks into the RV and discovers thermoses of blood and videos of girls talking about past lives. The backpacker, now revealed, strangles Senga, causing a crash that leaves her near-unconscious.

A disturbed tow-truck recovery man finds Senga and compels her to come with him. In his car, she sees a photo of a girl who appears in a video she’d seen earlier, learning that the girl is Christine, the recovery man’s dead sister. He takes Senga to a police station so she can report Nat's disappearance.

The police call Marek’s phone and are told that Nat has been with ‘him’ all weekend and that Senga is on medication. Senga realizes the authorities are compromised and that Nat is in danger, not just from the cult but from the people she’s with.

Senga spots the man and woman who photographed the crash at the truck stop. She assaults the female figure, and, fleeing with Nat, is pursued by the recovery man in his truck, ultimately leading them toward an abandoned research facility. The chase underscores the cult’s reach.

Inside the facility, Nat meets the Father, who uses a loudspeaker to address her and recruit her. The recovery man detonates a bomb, killing several cult members, while the Father reveals Senga’s past abortion as a tactic to break her resolve. The revelation destabilizes Senga as danger closes in.

The recovery man and the Father clash; in the struggle, the Father bites the recovery man's tongue and is killed. Senga detonates the last bomb, destroying the two men and breaking the cult’s grip. Senga and Nat escape, battered but alive.

Mother and daughter drive away in daylight, eager to put the ordeal behind them. At a gas station, they discover a razor blade—the Father's calling card—attached to the rearview mirror, a chilling reminder that danger may still follow them.