A wild animal smuggler, Clint Gray (portrayed by Dolph Lundgren), finds himself in a precarious situation while being pursued by the police on the highway. In a desperate attempt to escape, he crashes his van into a lake. Though he faces arrest, the public remains unaware that a bull shark he was transporting has escaped into the waters. Meanwhile, Carly, his three-year-old daughter, is left in the care of young sheriff Meredith (played by Sara Lane), as her mother is absent. Fast forward five years, and Clint is released on parole, with the distressing knowledge that both the shark and her two pups have thrived in the freshwater lake.
An elderly couple soon becomes victims of the menacing sharks, leading local authorities to misinterpret the incidents as bear attacks, resulting in the unnecessary killing of a bear in the vicinity. In a twist of fate, Meredith encounters a professor named Peter in a local restaurant who aptly doubts the bear theory. Peter bravely dives into the lake, retrieving evidence that confirms the presence of sharks. When Meredith sees this crucial proof and rushes to the beach to alert the residents, chaos ensues as multiple individuals suffer shark bites.
The stakes rise when Gareth Ross (played by Miles Doleac), a seasoned big fish catcher and television host, arrives seeking to capture the shark for his show. Tragically, Gareth underestimates the cunning nature of the sharks, who are not only more than one but also exhibit coordinated hunting tactics, resulting in his demise. In light of these events, Meredith issues a public reward for anyone who can successfully capture the creature.
Meredith becomes increasingly anxious about her adopted daughter reuniting with Clint, reinforcing the need for her elderly mother to keep vigilant. Meanwhile, she uncovers evidence linking Clint to the shark's introduction to the lake. Surprisingly, Clint has turned over a new leaf and declined to return to his former gang. During a brief encounter at Meredith's home, the father and daughter catch a glimpse of each other, but he retreats gently. However, Clint's criminal past catches up to him when his former boss threatens to harm Carly unless he retrieves the shark he was supposed to deliver five years prior.
Clint embarks on a boat, only to discover his daughter hiding onboard, having ventured out to reconnect with him. Their reunion brings joy, but Clint encourages her to return to her mother, promising regular visits. Unfortunately, the tranquility is shattered when Meredith's mother is attacked by a shark, and she heroically kills it to protect her.
In a dramatic turn of events, Meredith boards a small boat with Peter under the cover of darkness in search of Clint, who has now been falsely accused of kidnapping. Disaster strikes when a fisherman lured by the bounty is killed by a shark, leading to a collision with Meredith’s boat, which begins to sink. Gil undeterred, the duo floats with life jackets, hoping their mobile phone GPS can be a beacon for rescue.
The ensuing chaos unfolds as sharks attack, leading to Peter’s heroic but fatal struggle against one of them. Just when all seems lost, Clint comes to Meredith's aid, and she finds Carly with him, revealing that she sought him out. Grateful, Clint expresses his appreciation for Meredith caring for his daughter, but the reality of his actions weighs heavily as she reminds him of the lives lost due to his decisions. As the looming threat of a third shark emerges, it violently attacks their vessel, causing panic as Carly falls into the water.
In a heart-stopping moment, Clint plunges in to save her, fighting against the shark in a desperate bid for survival. Although wounded in the shoulder, he manages to send Carly back to safety, just as Meredith dives in to shoot the shark, killing it. Grateful for both their lives, Clint contemplates his desire to be part of Carly's life, revealing a changed man. They return to shore in a life-raft, where Meredith testifies to law enforcement about Clint's bravery, leading to a potential leniency in his sentencing. As Meredith assures Carly she will reunite with her father soon, a sense of hope prevails amidst the chaos.
