Sixteen-year-old Rowan is about to become one of the famed Leonodai Warriors - the elite shapeshifting fighters who protect the floating city Heliana from the world of Men - but when disaster strikes the city's children, Rowan sets out on her own, risking everything to save her beloved city.

The pristine floating city of the Heliana is home to winged-lion shapeshifters, the Leonodai. Protected from the world of humans by an elite group of warriors, the Heliana has only known peace. After years of brutal training, Rowan is ready to prove her loyalty to the city and her people to become one of the Leonodai warriors. When a deadly disease strikes the city's children, the warriors are sent on a dangerous mission to find a fabled panacea deep within enemy lands. Left behind, Rowan learns a devastating truth that could compromise the mission-- and the fate of the Heliana itself. -- Adapted from jacket.