Airships, experiments, immortal beasts-a maid's work is never done! After being betrayed by a goblin they thought was an ally, Bostwick and Emmaline must help Queen Delilah collect pieces of the map of Styx, which lie scattered across the globe. Aided by a flying machine, they encounter corrupt dictators, clumsy goat girls, immortal beasts, and-most frightening of all-a love potion gone horribly wrong. Meanwhile, Millicent finds herself in the mysterious, black-and-white city of Chiaroscuro. Sebastian reveals that the city is in danger, and he needs her to cast a spell from her old magic books-a spell which she alone knows. But who wrote those books in the first place, and what do they have to do with Chiaroscuro? To explain, Sebastian shows Millicent visions of life at Melieh's Academy of Magic hundreds of years ago. As she learns more about the school, Sebastian's past, and the truth behind the test that barred her from the Academy, she must make a choice that could mean life or death.