The fourth and final book in a steampunk YA adventure series, from Orbit's New York Times bestselling author of the Parasol Protectorate series.

When a dastardly Pickleman plot comes to fruition, only Sophronia can save her friends, her school, and all of London...but at what cost? Our proper young heroine puts her training and skills to the test in this highly anticipated conclusion of the rousing, intriguing, and always polished New York Times bestselling Finishing School series!