Recently divorced Helen Grace (Mary-Louise Parker) moves into the Spiderwick Estate with her children when it is given to her by her elderly aunt Lucinda (Joan Plowright), though identical twins Jared and Simon (Freddie Highmore) and their older sister Mallory (Sarah Bolger) do not want to move from the city. When Jared uncovers a dumbwaiter system behind a wall, Jared finds a monogrammed key and discovers the study of the late owner of the estate, Arthur Spiderwick (David Strathairn). Jared uses the key to open a chest. In it, he finds Spiderwick's field guide to faeries; although an attached note warns him not to read it, he does so anyway.