On the night she turns eighteen, Princess Cassia Aurelian's magic reaches full strength, and with it, the right to be courted. Five suitors gather at her birthday gala, each bearing a gift meant to prove his worth.

Then the Dark King arrives. Uninvited, covered in mud, and feared by everyone who knows his name. He brings no treasure, only a single black rose, and he takes her hand for the first dance before anyone can stop him.

Cassia should turn him away. Everyone warns her of his cruelty, of the traitors he has executed with his own hand. But when a suitor is poisoned and a killer comes for her in the night, it is the king no one trusts who keeps reaching her first.

Her magic is slipping out of her control, and the man everyone fears may be the only one who can steady it. Trusting him means ignoring every warning. Refusing him could cost her life.