Fiona never should have entered the Fae realm. But when her father is cursed and dying, she has no choice but to risk the one place humans are forbidden to go—the Nyx River Marketplace—in search of a Fae potion that might save him. Then her little sister disappears. Trapped inside a snow globe by a cruel Fae bargain, Winnie is condemned to sing for a thousand years. Fiona will do anything to free her. Even become a slave to the ruthless Fae King. The bargain is simple: he will free Winnie and give Fiona the potion to save her father. In return, Fiona belongs to him. She expects cruelty. She expects hatred. What she doesn't expect is the strange pull between them—or the burning marks that appear on her wrists when he touches her. Fated mate marks. But that's impossible. Fae do not have human mates. And the King refuses to believe the bond is real. As Fiona is forced to remain within his palace, hatred slowly gives way to something far more dangerous. The bond between them grows stronger with every stolen glance, every forbidden touch, and every secret the King refuses to reveal. But there is something neither of them knows. Something hidden in Fiona's blood. Because Fiona may not be as human as she has always believed. And the truth about what she is could change the fate of both the human and Fae realms forever.