Plot
Teenager Michael Emerson, his younger brother Sam, and their recently divorced mother Lucy move to the seaside town of Santa Carla, California. They live with Lucy's eccentric father, to whom they refer solely as Grandpa. Lucy takes a job at a video store owned by Max, who takes a romantic interest in her. At the local comic book store, Sam meets brothers Edgar and Alan Frog, self-proclaimed vampire hunters who believe vampires have infested the town.
Michael becomes drawn to Star, a beautiful girl he meets on the boardwalk. He notices her spending time with David, the charismatic leader of a local gang that includes Paul, Dwayne, and Marko. Sensing Michael's interest in Star, David challenges him to keep up with them on their motorcycles, leading him to their hideout in a former luxury hotel buried during the 1906 San Francisco earthquake. There, David manipulates Michael's perception, making his food appear as maggots or worms, before offering him a bottle of red liquid. Although Star warns him that it contains blood, Michael drinks it. David's gang then leads him to a railway bridge, where they hang suspended over a vast drop, each member eventually letting go and disappearing into the fog. Michael, unable to hold on, falls, but he inexplicably lands safely in his bed.
Michael begins to change; he becomes sensitive to light, finds normal food revolting, and notices his reflection fading. He develops a craving for blood and nearly attacks Sam, but Sam's dog, Nanook, intervenes and stops him. Though terrified, Sam agrees to help Michael and deduces that he is turning into a vampire. His transformation will only be complete, though, if he feeds on human blood, and it may be reversible if they kill the head vampire. Sam, Edgar, and Alan suspect Max is the head vampire, but after Max is invited to dinner at Lucy's house, they notice he has a reflection and has no reaction to garlic or holy water.
David and his gang attempt to push Michael into killing by revealing their true monstrous faces and demonstrating their ability to fly as they murder a group of partygoers. Michael resists the temptation to feed. Later, Star confides in Michael that Laddie, a young member of the gang, and she are also only partly transformed, as they, too, have refused to kill. She admits that David wanted her to kill Michael to complete her transformation. Determined to save her, Michael leads Sam and the Frog brothers to the gang's lair during the day while the vampires are sleeping. They stake and kill Marko, whose pained screams awaken the others. The boys narrowly escape with Star and Laddie, as David vows to hunt them down that night.
Michael, Sam, and the Frog brothers prepare for the gang's impending assault, arming themselves with holy water, a longbow, and stakes. As night falls, David's gang breaks into the Emerson home. In the ensuing fight, Sam, Nanook, and the Frog brothers kill Paul and Dwayne, while Michael takes on David. Michael resists David's urging to accept his transformation and impales him on Grandpa's collection of antlers. Despite David's death, Michael's transformation is not undone, leading the group to realize that David was not the head vampire.
Lucy and Max return home from their date. Spotting David's lifeless body, Max confesses he is the head vampire. He reveals he passed the boys' earlier vampire tests because he had been invited into their home, making him immune to those vulnerabilities. Max explains his desire to create a vampire family and that he ordered David to turn Michael and Sam to compel Lucy to join the family as mother to the boys. To save Sam from being killed on the spot by Max, Lucy agrees to Max's demands. Before Max can turn her, though, Grandpa crashes his truck through the wall, impaling Max with a large wooden fence post and causing him to explode. With Max's death, Michael, Star, and Laddie revert to normal. Grandpa then grumbles, "One thing about living in Santa Carla I never could stomach—all the damn vampires."
