Twelve-year-old Daisy's prospects are grim. In her mining town, Coal Top, boys leave school at 12 to work in the mines, and girls leave to work as servants for the rich people. Daisy can't stomach the idea of that kind of life, but what choice does she have? Especially when her family is counting on her wages to survive.
All that changes when Daisy is recruited for a dangerous competition in which daring (and ideally, orphaned children) train flying horses to battle the monsters that lurk beneath Coal Top. If she wins, she'll earn a fortune for her struggling family. If she fails . . . her family will have one less mouth to feed.
But the situation proves even more sinister than Daisy realizes, and in addition to fighting for her life, she finds herself uncovering a dangerous mystery at the heart of Coal Top's struggles-a mystery that the charismatic ringleader Mortimer Good will do anything to protect.