Desire Unmatched — Lynne Silver

Book four in the Coded for Love series.

Genetically enhanced soldier Xander Bristack has spent his life under the imposing rule of his dictatorial, controlling father. Under his father's watch, he is the Program's deadliest and coldest killer. But when Xander is kidnapped by enemies of the Program, only one thing motivates him to escape. His true match, the sexy Emma Harrison.

He's been obsessed with Emma from afar, yearning to have her in his life and in his bed, but knowing he should never involve the beautiful blonde in his messed-up world. However, when Xander breaks out of his prison and returns home, Emma refuses to let him keep his distance, enticing him to surrender to the heat between them. She teaches him that passion trumps duty and love doesn't mean blind obedience. His desire for her cracks the shell he's hidden in his whole life.