Vows Written in Blood follows Iris Holloway, an anonymous investigative ghostwriter who uncovers secrets capable of destroying Europe’s most feared billionaire, Sebastian Crowe. Instead of silencing her, Sebastian forces Iris into a one-year contract marriage to protect his empire. Trapped in a mansion filled with secrets and control, Iris finds herself entangled in a dangerous psychological game where hatred slowly transforms into obsession. As the truth about Sebastian’s past emerges, Iris must decide whether to expose the monster she married or stand beside him and rewrite the rules of power and survival.