Cavas by Laurann Dohner

Career military man Cavas Vellar has joined his older brother, Cathian, aboard The Vorge for one purpose—to rescue their youngest littermate. Their father has resorted to having him kidnapped to hide one of his most vile secrets. They need to go down onto a planet full of criminals, find Crath, and rescue him. This mission is the most important one Cavas has ever led.
Jill was betrayed when Earth sold her into alien slavery. She owes her life to Cavas and the Vorge crew for taking her out of a cell and to their ship. When she learns why they were on that planet to begin with…she feels it’s her duty to help them find their missing brother. Even if it means losing her recently gained freedom.
One determined alien on a mission. One woman who notices how sexy he is. This is their story.