At the end of the school year, Kendra and her brother Seth find themselves racing back to Fablehaven, a refuge for mythical and magical creatures. Grandpa Sorenson invites three specialists -- a potion master, a collector of magical relics, and a trapper of mystical creatures -- to help protect the property from the Society of the Evening Star, an ancient organization determined to steal a hidden artifact of great power. Time is running out. If the artifact falls into the wrong hands, it could mean the downfall of other preserves and possibly the world.