10-year-old Finn is terrified to learn his family is relocating from sunny California to Maine in the scariest house he has ever seen! Convinced that his new house is haunted, Finn sets up a series of elaborate traps to catch the “ghost” in action. Left home alone with his sister while their parents are stranded across town, Finn’s traps catch a new target – a group of thieves who have targeted Finn’s house. Finn Baxter sets up booby traps to catch the ghost of his new home's former occupant, then discovers that he must protect the house and his sister from three bumbling art thieves.