Assassin by Cyndi Friberg

Torrin’s simple mission is seriously complicated when he finds Arrista, a lovely Sarronti female, in need of rescue. The Sarronti resent the Outcasts and continually sabotage their efforts to build a settlement on the primitive planet. But Arrista isn’t just any Sarronti. She’s the personal servant of one of the most powerful Sarronti. The information Arrista can provide would be vitally important to the Outcasts, so Torrin is ordered to use their mutual attraction to question her.
Arrista has been taught to fear and mistrust the savage Outcasts, so why does she find Torrin so fascinating, so desirable? It’s not just his muscular body and rugged features. He is kinder and more protective than any male she has ever known. She is drawn to him by a force so compelling it leaves her no choice but surrender. She wants him, needs him, but can she trust him not to break her heart?