Phears, an evil ghost, wants eleven-year-old Max to help him capture the ghosts of two children whose parents once trapped him, and he sends a Berserker Ghoul to possess Max and convince him to obey.

When his brother, Colin, takes the pendant in which the ghostly Nicky and Tara's parents may be trapped, Max must follow him to Camp Snake Lake and try to retrieve the pendant before evil ghosts find it.

Max's twelfth birthday party turns into a major disaster when ghosts Nicky and Tara boycott it and sinister events spin out of control.

Max already shares his house with two young ghosts that only he can see, but things get really bad when an evil ghost decides to share his body.