Rake of the Heart - The Wild Hearts Trilogy, #3

Fate has dealt a cruel blow to Jean-Michel de Chambois, once a French viscount but now an American citizen, drawing him into a secret life on the fringes of piracy. Revenge may be sweet, but he discovers there are greater forces at work when Sophie Lafleur, fleeing her own demons, embroils him in a far more dangerous game. Both Jean-Michel and Sophie discover that vows only whet the appetite for forbidden desires - and that those vows could cost them their hearts as well as their lives. This is the third and final book in the Wild Hearts Trilogy.