My dangerous duke - Gaelen Foley

The formidable, rugged, Rohan Kilburn, Duke of Warrington is a top assassin for the Order. Known for his superstitious streak, he has made a point of keeping his heart immune to love, despite his many conquests.
But on one cold winter's night when he returns to his broody seaside castle, he finds that his errant tenants have provided him with a beautiful young woman as a bed-warmer.

But Kate Madsen is no harlot. She is the innocent victim of a kidnapping plot, shy but independent, with intelligent, beguiling eyes. As Rohan and Kate work together to unravel the truth surrounding an ancient curse that could destroy them both, their budding attraction begins to ignite. But when the unthinkable happens, it's up to Kate to shatter the curse that could prevent her Dangerous Duke from becoming her ideal husband.