When Jared, Mallory and Simon move into their new home, they discover a book that used to belong to their great-uncle, Arthur Spiderwick's Field Guide to the Fantastic World Around You, and realise they are not alone. The house is full of faeries and other mythical creatures, and they will do anything in their power to stop the children telling the world about them. After their incredible discovery, the Grace children have many questions, and with the aid of the seeing stone, some of them are answered. They find out the fate of their missing cat, and begin to realise the true nature of the secret world around them - and the danger they are in...