For eighteen years a girl with no name, a Redwing, has been hidden away in a small attic room within a city of hissing pipes and curving temples perched on the side of the great volcano, Mol, while her sister, Jey--identical except for her eyes--has lived her life in public as an only child. Their father had hoped the hidden girl would one day grow up to be a normal human girl and not the wicked creature mythology has promised, so he secretly spared her life as an infant. But when she switches places with her sister, striking up a flirtation with the son of the Empress while working in the royal gardens and gets attacked by two suspicious priests on her journey home, she is forced to call forth fire to protect herself, unleashing her previously dormant powers and letting her secret out. She soon catches the attention of a cult with a thousand year old grudge as well as a group of underground rebels, both seeking her for their own gain. But when her sister goes missing and the Redwing uncovers a great plot to awaken Mol and bring fiery destruction upon them all, she is forced to embrace her powers.