Eye of the Mother. Dryden Universe, #4

A distant star explodes. The ripples of its passing will rock the Empire. When fate throws Brent Walker and Tian Axmar together, it's strictly a business arrangement. She's an Imperial agent with a problem to solve, he's a space jockey with an empty bank balance and a tramp freighter for hire. Someone's murdering Yrmaks and Humans, leaving a cryptic calling card and a trail of chaos designed to spark war.
To stop it, Tian and Brent must delve deep into Yrmak culture-and into danger. As the conspiracy unravels, loyalty, love, and the fate of two species hang in the balance. Before it's over, both will face choices that will change them forever.