Beneath

Six high school seniors head to a secluded lake for a last day together. They travel by boat and settle in for a day of roughhousing and music, trying to ignore the warnings. The mood is part excitement, part unease as they drift away from land.

Johnny meets Mr. Parks, a friend of his grandfather, who cautions him to be careful in the lake. Johnny promises to show restraint, but the rest of the group remains reckless. The warning plants the seed of foreboding that runs through the day.

The group ignores the warning and creates disturbances on the boat, pushing boundaries and testing luck. Johnny tries to keep some order, but the others push forward anyway. The water around them feels ominous while they laugh in defiance.

An unknown object brushes against them underwater, startling the group. They attempt to row back toward shore, but the lake seems to resist their efforts. A sense of being watched lingers as ripples spread outward.

Deb reaches for a recovered oar and is suddenly bitten by a giant fish, bleeding to death. The others scramble to row with the remaining oar, terror replacing their earlier bravado. The incident shatters any remaining sense of safety on the lake.

With one oar left, the fish destroys it as it attacks again. In a desperate move, they throw Deb's body overboard to distract the predator, but the tactic fails. The boat is left stranded and the survivors are stranded with no easy escape.

Zeke tries to persuade the group to throw Johnny overboard, then jumps overboard himself. The fish chases him, and his GoPro captures the horrifying pursuit. The others are left in shock as the group’s cohesion crumbles.

Johnny makes it to shore in a motorboat and sets out to rescue the others, trying to tow the boat with a rope. The fish bumps the motor and the rope tightens around his neck, cutting off air. Kitty's frantic attempt to cut the rope comes too late, and Johnny dies.

Kitty, Matt, and Simon throw Johnny's body into the water to keep the fish away from their boat, but the predator does not immediately consume him. A fresh round of accusations and anger erupts among the survivors as they struggle to decide who is to blame.

Matt throws Kitty into the lake after a confrontation sparked by Zeke's insinuations about Kitty. She swims toward the shore to seek safety while the two brothers fight and tumble into the water. Simon suffers a head injury, blood further attracting the fish.

As the struggle continues, Matt is killed by the fish and Simon manages to reach the shore with injuries. Blood in the water draws more attention from the predator. The remaining survivors are left to confront the lake’s deadly secret.

Kitty notices Johnny's body and removes his tooth necklace, hoping it will protect her. The fish attacks the corpse, and Kitty makes a desperate swim for the shore. She is confronted by a crazed Simon and is drowned in the shallows.

Night deepens as Mr. Parks appears and asks about Johnny. Simon claims everyone is dead, but Parks reveals he knows what happened, holding a gun and Zeke's GoPro. He demands that Simon return to the lake, underscoring the predator's lingering presence.

Parks shoots Simon multiple times; Simon is dragged back into the water and devoured by the fish. The lake's violence ends with a chilling finality as blood stains the water. Johnny's necklace lies on the lake bed as a quiet relic of the tragedy.

Johnny's tooth necklace is seen on the lake bed and then disappears as the lake winds down with blood covering the surface. The predator's presence lingers, leaving only memories of what happened and a haunted silence over the water.