Brother Gray and his sister Joey embark on an adventurous whitewater rafting trip along with their friends Trevor, Karissa, and Van. The group sets off for a day filled with excitement, stopping to relax by the river for some swimming, bathing, and drinks. As the sun sets and laughter fills the air around a campfire, the atmosphere takes a dark turn when Trevor and Van step away briefly, only for Trevor to suddenly cry out for help, claiming Van has tripped and fallen.
With urgency, Gray instructs Trevor to call for assistance through the Ranger's phone, but he soon learns that the phone is out of commission. In a quiet moment, Van confides in Joey that Trevor had actually assaulted her. Given her medical background, Joey swiftly assesses Van, concluding that she has sustained a serious injury – a skull fracture.
Once back on the raft, the group optimistically believes that help is merely a couple of hours away. However, things take a dire turn when Van experiences a seizure, and Joey must step in to calm her down. In a moment of confusion, Gray directs Trevor to steer the raft towards safety, but in a shocking turn of events, Trevor goes against these instructions, causing the raft to capsize. Joey realizes that Trevor may have intentionally flipped the boat, fearing that Van might reveal what he has done.
As dawn breaks, the group decides to leave the raft and climb a hill to seek medical assistance. During this journey, Trevor reveals his troubled past, confessing to having spent three years in prison, and he implores Gray not to send him back. They eventually encounter a ranger and urgently request a helicopter to airlift Van due to her critical condition. However, panic strikes when Trevor stabs the ranger and destroys the radio, snatching the ranger's weapon. In a chilling demand, he coerces Gray into throwing the ranger's body off a cliff, resulting in an explosive aftermath.
The situation escalates further as Trevor asserts that the ranger is dead and orders the group to row towards Canada. Tragically, during their escape, Van succumbs to her injuries, leaving the group devastated. While navigating through the river, Joey attempts to attract help from a passerby on a bridge, yet Trevor cunningly manipulates the situation to retain control.
That night, they are forced to bury Van, while Trevor ties up the remaining friends to prevent their escape. In the darkness, a stranger who had witnessed the prior events attempts to confront Trevor, but is tragically shot down. Unbeknownst to the rest, Karissa manages to take the dead man's Swiss army knife during the chaos.
The following day, as the girls remain bound, Gray is the only one rowing the boat. In a moment of resolve, Karissa uses the knife to sabotage the raft, prompting an emergency landing to patch up the damage. In a desperate struggle, Gray confronts Trevor but is shot in the scuffle. Seizing the opportunity, Karissa escapes with Joey, leading to a frantic chase as they dart in different directions to evade Trevor.
As the tension escalates, Joey cleverly slips away from Trevor and returns to find Gray gravely wounded. Just as the siblings attempt to escape down the river, Trevor closes in on them. In a fierce confrontation, Joey is stabbed in the back, but Gray valiantly intervenes, throwing Trevor into the river, which ultimately results in Gray's own downfall as he is drowned in the chaotic waters. Meanwhile, in a stroke of luck, Karissa arrives with a helicopter and bravely rescues Joey, bringing a glimmer of hope amidst the harrowing events they endured.
