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 where their grandfather is caretaker. The Society of the Evening Star, an ancient organization determined to infiltrate the preserve and steal a hidden artifact of great power, is storming the gates. If the artifact falls into the wrong hands, it could mean the downfall of other preserves and possibly the world. Time is running out.