Book Three of The Blackthorn Brothers Series.
He was named Don John Blackthorn, but his family call him Black Jack (although not within earshot), because of his mysterious ways, yes, but mostly because he allows no one close to him, reveals nothing of himself. But Jack has a problem, and her name is Tess Fonteneau. She's the daughter of his mentor in the fine art of clandestine adventure, and she sees him all too well.
Now his mentor, his friend, this man who knows too many dangerous secrets, has disappeared, and it will take Jack and Tess both to find him, save him, before it is too late. Even if they both believe it's already too late for them to rekindle the flame that that briefly burned between them, and then just as quickly died. But is it ever too late for love?