The hilarious first book in a middle-grade fantasy trilogy about the magical rivers that run through the sewers of London and shape history in ways you'd never learn in school.

Magic is real. History is a big, fat lie.

Before Hyacinth Hayward moves from Illinois to London, she reads up on the city's history. Too bad for her. Because the books are wrong. The truth is, London was built on magical rivers, and all the major events in its past have been about people trying to control the magic.

Hyacinth discovers this when her mom is kidnapped. In the chase to get her back, Hyacinth encounters a giant intelligent pig in a bathing suit, a boy with amnesia, an adorable tosher (whatever that is), a sarcastic old lady, and a very sketchy unicorn. Somehow Hyacinth has to figure out who to trust, so she can save her mom and, oh yeah, not cause a second Great Fire of London.