Every thirteen years, twelve coastal villages sacrifice one girl to the Bride Tide—a deadly contest where human legs become mermaid tails and only one bride is promised to survive.
Isla Reed, a poor fisher girl, is expected to die first. Instead, the Black Tide refuses to consume her. She becomes the only bride who can shift between human, mermaid, and monster without losing her mind.
As the royal court turns the girls’ suffering into entertainment, Isla uncovers the truth: the winner does not marry the Sea God. She becomes a living lock, imprisoned beneath the sea forever.
Now Isla must turn the deadly tide against the Crown, awaken the voices of the murdered brides, and resist the dangerously handsome Sea God who wants to protect her—but may only be offering another cage.
