Jhereg

Jhereg by Brust, Steven. mass_market edition. ISBN: 9780441385546.

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--Dragaeras 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 Vlads past in this, and in other, lives.