Jhereg.

The first to be published, this is actually the fourth novel in the timeline of the VLAD TALTOS series. The books recount the adventures of the wisecracking hired killer Vlad, a human on a planet mainly inhabited by the long-lived, extremely tall sorcerers known as the Dragaerans. One of the most powerful bosses in the Jhereg—Dragaera's premier criminal organization—hires Vlad, one of their guild members, to assassinate Mellar, who stole millions from the Jhereg leadership and fled. Unfortunately, this thief turns out to be protected in a way that makes it difficult for Vlad to do his job without gaining the permanent enmity of a friend. The reader also learns more about Vlad's past in this, and in other, lives.