The film is based on the best-selling novel of the same name by Holly Black and Tony DiTerlizzi. Single mother Grace (Mary-Louise Parker) moves into the ancestral home of Spitwick with her twin sons Jared and Simon (Freddie Highmore) and her eldest daughter Mallory (Sarah Bolger), and encounters a series of strange things. During his own investigation, Jared finds the elf exploration guide of his great-aunt father Arthur Spitwick (David Strathairn) in the attic. Despite a warning on the cover of the book, Jared reads the guide and then sees one of the elves described in the book, the brown elf Simbertek (voiced by Martin Short). Simbertek warns Jared not to take the book outside the protection circle of the ancestral home of Spectwick, in case the evil spirit Maugras (Nick Nolte) takes the guide for himself and harms other elves. But Maugras's men have learned that the guide has been rediscovered and mistakenly arrested Simon. In order to protect the guide and their family, the three siblings must fight Maugras to the death...