Six high school seniors head out to a secluded lake for a last day together, a plan that starts with carefree chatter and quickly shifts to tension as the surface of the water mirrors their unease. The group is made up of Johnny, Zeke, Kitty, Deb (Kitty’s friend), Kitty’s boyfriend Matt, and Matt’s brother Simon. Early on, Johnny runs into Mr. Parks, a friend of his grandfather, who warns him to be careful around the lake. Johnny promises to be respectful, but the others remain restless and disruptive as they drift in a boat, pushing the boundaries of the quiet shoreline.
From the moment they settle in, the teens sense something off beneath the water. An unseen force seems to brush against them, a sensation that grows more menacing as they attempt to row back to shore. They lose one oar to the lake’s depths, and Deb reaches down to retrieve it, only to be seized by a colossal fish that bites hard and bleeds the lake with her life. The group scrambles to return to land, fighting to row with their dwindling resources, but the giant predator continues to destroy their remaining oar, leaving them stranded and vulnerable in the middle of the lake.
In the chaos that follows, Kitty accuses Johnny of knowing about the danger after he previously tried to give her a protective necklace. Tension spikes as Zeke tries to rally the group to oust Johnny, but he is the one who dives overboard and disappears, swallowed by the same deadly creature that has begun to stalk them. The fish’s appetite proves relentless as Zeke’s GoPro captures the terrifying sequence, a cruel record of fear turning to fatal inevitability.
Johnny eventually makes it to shore and devises a desperate plan to rescue his friends. He moves toward safety in a motor boat, attempting to tow the others by tying a rope, only to have the fish strike the vessel and spin it violently. The rope tightens around Johnny’s neck, and despite Kitty’s frantic attempts to cut it free, he dies, pulled into the lake’s dark heart.
As a gruesome tactic to distract the fish, Kitty, Matt, and Simon throw Johnny’s body back into the water, hoping the predator will bite elsewhere. Instead, the fish remains fixated on the body, and Johnny’s fate becomes a grim focal point for the survivors’ escalating fear. The trio’s earlier rifts flare into open hostility: Kitty’s alleged complicity with the brothers, Matt’s anger, and Simon’s unsettling presence drive them toward further fractures. Matt shoves Kitty into the water in a desperate moment, and she swims away, leaving the brothers to unravel their rivalry. A brutal brawl between the siblings ends with both of them tumbling into the lake; Simon suffers a head injury, and the sight of his blood draws the fish’s attention.
Matt hurries to help his brother but is driven away and fatally drawn into the predator’s path as Simon scrambles toward the shore. Kitty, meanwhile, gazes at Johnny’s body drifting nearby and, driven by a mix of superstition and fear, removes Johnny’s necklace, believing it will offer protection. The moment the necklace comes off, the fish ruthlessly attacks Johnny’s corpse, underscoring the lake’s merciless nature. Kitty manages to reach the shore, but she is confronted by a mentally unstable Simon, who drowns her in the shallows despite her pleas for mercy.
Night falls, leaving a bloodied and exhausted Simon to confront Mr. Parks. The elder man asks about Johnny, and Simon says everyone is dead. Mr. Parks expresses quiet sorrow for Johnny’s death and insists that Simon return to the lake. When Simon refuses, a shocking confrontation reveals Mr. Parks armed with a gun—along with Zeke’s GoPro—confirming that he knows exactly what happened. He fires at Simon, who dives back into the water, only to be dragged beneath the surface and devoured by the same insatiable fish. The lake’s bed bears witness to the horror as Johnny’s tooth necklace appears briefly on the shore before sinking again, overtaken by the lake’s bloody and silent finality.
