That perfect someone - Johanna Lindsey

Nine years ago Richard Allen fled England when his greedy, ambitious father, the Earl of Manford, betrothed him to Julia Miller, the daughter of London's wealthiest merchant. The pair can't stand each other and Richard takes to the sea, determined to live his own life.

In the Caribbean, he joins a band of treasure-hunting pirates and adopts the persona of a Frenchman named Jean-Paul. But when he is forced to return to England on an errand for his captain, he finds himself completely smitten with a married woman, Georgina Mallory. Despite her indifference to him, not to mention her husbands threats against him, he persists in seeking her affections. But when he attempts to woo her at a ball, the last thing he expects is to come face to face with Julia Miller.

Despite his son abandoning her, the Earl has refused to break the marriage contract. But when Julia tries to wreak her revenge, not all goes quite according to plan...