Foreigner - C. J. Cherryh

THE SPACE OPERA CLASSIC: Discover "one of the best long-running science fiction series in existence" (Publishers Weekly)!
A sole human diplomat navigates a world inhabited by hostile, intelligent aliens—and learns the consequences of first contact.
It had been nearly 5 centuries since the starship Phoenix, lost in space and desperately searching for the nearest G5 star, had encountered the planet of the atevi. On this alien world, law was kept by the use of registered assassination; alliances were defined by individual loyalties, not geographical borders; and war became inevitable once humans and one faction of atevi established a working relationship. It was a war that humans had no chance of winning on this planet so many light-years from home.
Now, nearly 200 years after that conflict, humanity has traded its advanced technology for peace and an island refuge that no atevi will ever visit. But then the sole human allowed into atevi society is marked for an assassin's bullet. The work of an isolated lunatic? The interests of a particular faction? Or the consequence of one human's fondness for a species which has 14 words for betrayal and not a single word for love?