Just your typical ‘move into an old creepy house, weird stuff starts happening, one of the kids gets blamed, and then they find a book that explains the existence of fairies/faeries/fey which solves their problems... while at the same time causing many more problems’. Happens every day.
After finding a mysterious, handmade field guide in the attic of the ramshackle old mansion they’ve just moved into, Jared; his twin brother, Simon; and their older sister, Mallory, discover that there’s a magical and maybe dangerous world existing parallel to our own—the world of faerie.