Novak (Adam Scott) is part of a diving team hired by Sheriff Julie Forester (Elisabeth Shue) to investigate an under-ground cave that has been discovered in the lake. While searching it, both members of Novak's diving team are eaten by piranhas. Novak manages to capture one and shows it to Carl Goodman (Christopher Lloyd) who warns the pair that they should close the lake. While trying to warn the spring-break partiers the piranhas attack. Novak tries to help save as many of the partiers as he can, boarding a jet-ski and shooting piranhas while letting people ride with him to shore. When Julies son Jake (Steven R. McQueen) phones telling her that he is trapped on a sinking boat in the middle of the lake, both Julie and Novak leave to save him. They arrive at the boat and tie the boats together. Novak helps save Jake, Kelly (Jessica Szohr), Laura (Brooklynn Proulx) and Zane (Sage Ryan) he realizes that the piranahas have only been children. Suddenly an adult piranha attacks Novak, killing him.