Mark of Eon by Anna Hackett
Oil and water. Fire and ice. Terran space marine and rugged alien warrior.
Space marine Lieutenant Jamie Park has a reputation as tough as steel…just the way she likes it. A horrible childhood and her marine training have forged her into a strong woman, and she’s never seen a fight she’d back down from. Taking on the voracious insectoid Kantos is her focus, even if that means being assigned to the Eon warship, the Desteron, and working with the one arrogant alien warrior who’s seen her vulnerable and weak.
Medical Commander Aydin Kann-Ath lives to be the perfect warrior and doctor. All his life, he’s worked to restore his family’s tarnished honor. He has no room in his life for anything but his work, and that includes a headstrong, battle-hardened Terran who — even when injured — refuses to follow orders. Yet every minute he spends with Jamie, she ignites both his temper and his desire, and he can’t seem to stay away.
With every interaction, Aydin finds himself fascinated by Jamie’s courage and spirit, and Jamie finds herself consumed by a fiery attraction that terrifies her. On a dangerous hunt to find symbiont lifeforms that have been stolen by the Kantos, the pair can’t ignore their passionate connection. But the evil Kantos threaten not only their lives, but the fate of the galaxy, unless Jamie and Aydin sacrifice it all to stop them.