Ruined Castle Books in Order

Ruined Castle is a dark billionaire trilogy with a strong Gothic streak. The setup drops a young woman with a broken dance career into the orbit of a wealthy, dangerous Scottish single father, then strands them in a world of castles, blackmail, grief, and family secrets. The series starts with the prequel The Sinner, then moves into The Beast, The Nanny, and The Caress.

This is a one-couple arc, so the tension builds across the books instead of resolving in one shot. Ella walks into Keir's life thinking she is taking a job. Pretty quickly, she is also taking on his daughter, his enemies, his damaged past, and the truth that his house is not a safe place to want anything. Keir has the usual billionaire power, but the series keeps reminding you that power does not mean peace. He is guarded, controlling, and used to making hard choices before anybody can question him.

The Scottish setting really helps. Moonlit halls, private wings, old money, and family history give the books a more enclosed, moody feel than a standard office romance. There is still heat, obviously, but there is also suspense carrying the story forward.

If you like the idea of Beauty and the Beast with more blackmail, more secrets, and a nanny setup that gets very complicated very fast, Ruined Castle is a strong pick.