She didn't inherit her empire.She bled for it.Sienna Calabrese is twenty-seven years old and the most feared name in Southern Italy. She buried her father, outlived her brothers, and rebuilt a crumbling mafia dynasty with nothing but sharp instincts and a spine made of steel. She answers to no one. She needs no one. She has spent four years making sure everyone in her world understands both of those things.Then the council calls.The Montanari are coming — methodical, ruthless, and already dismantling everything she built piece by piece. The solution, according to five old men in a Rome back room, is an alliance. A permanent one. The old-fashioned kind.A marriage.To him.Nikolai Vasin is thirty-three, Russian Bratva, and the coldest man Sienna has ever sat across a table from. He doesn't raise his voice. He doesn't make threats. He doesn't need to. He has the kind of stillness that makes rooms go quiet before he speaks — the kind that tells you, without a single word, that he has already thought of every move you're about to make and decided what to do about all of them.He agreed to the contract.She agreed to the contract.Neither of them agreed to this.A Debt in Blood is the story of two people who are equally dangerous, equally guarded, and equally certain they are immune to each other.They are not immune to each other.But they will spend a very long time pretending to be.