"Twins Asya and Izaveta were separated at 10 after a ceremony determined Izaveta would be the next queen of Tourin, while Asya would be the next Firebird, a creature who demands a price in exchange for magic. Six years later, after the sudden death of their mother, they are reunited as the time has come to fulfill their predestined roles. Each maintains secrets as they struggle to get to know one another again. Izaveta has been taught everything...

In the aftermath of a war where Automae took over the kingdom of Rabu and bent humanity to their will, Ayla takes a job as a servant in the house of the sovereign for one purpose: to get revenge for her family's death by killing his daughter. Lady Crier, the heiress, was Made to be a perfect ruler of the kingdom, but she no longer knows if that is what she wants once she discovers some of her father's cruel secrets. Between this betrayal, and a betrothed...

The human revolution has risen against the Automae of Rabu, and at its heart is Ayla. Once a handmaiden, now a fugitive, Ayla narrowly escaped the palace of Lady Crier, the girl she would've killed if they hadn't fallen in love first. Unbeknownst to Ayla, Crier escaped as well, joining with rebels and determined to find her way back to her love. When their paths finally cross and Ayla is charged to destroy the Iron Heart, neither girl is prepared...