When the Bennett family empire teeters on the edge of collapse, Iris Bennett is forced into an arranged marriage with Cassian Laurent—the ruthless billionaire heir to the family her own has hated for generations. Their union is meant to save two powerful corporations, but to Iris, it is nothing more than a vow signed in sacrifice. On their wedding day, a stranger crashes the ceremony with a chilling warning: if they marry, someone will die before sunset. Moments later, a deadly attack proves the warning was real. As mysterious threats close in, Iris and Cassian are drawn into a dangerous web of buried family secrets, hidden passages, coded messages, and a decades-old conspiracy that refuses to stay buried. Every clue leads them deeper into a war neither of them started, where allies become suspects and every answer raises a deadlier question. Bound by a marriage built on revenge instead of love, they must decide whether to trust each other or become the next victims of a ruthless enemy determined to destroy both the Bennett and Laurent families. But the greatest betrayal isn't waiting in the shadows. It's hidden within the vows that brought them together.