Twelve-year-old Autumn Malog is a servant at the enchanting Inglenook School, where young magicians study to become the king's future monster-hunters. Along with her Gran and three too many older brothers, she works as a beastkeeper, tending to Inglenook's menagerie of terrifying monsters.

But when she isn't mucking out the wyvern stalls or coaxing the resident boggart to behave, Autumn searches for clues about her twin brother's mysterious disappearance. Everyone else thinks he was devoured by the feared Hollow Dragon, but Autumn is convinced she's heard--and glimpsed--him calling to her from within the castle walls. But who will believe a lowly servant?

So when Cai Morrigan, the "Chosen One" prophesied to one day destroy the Hollow Dragon, comes to her for help, Autumn agrees on one condition: Together, they'll search for her brother and uncover the dark truth at the heart of enchanting Inglenook School once and for all.