The Traitor Spy Trilogy by Trudi Canavan (2 Paperbacks + 1 HC/DJ)
Most of her friend's family has been murdered -- the latest in a long line of assassinations to plague the leading Thieves of the city. There has always been rivalry, but now the Thieves are waging a deadly underworld war, and it appears they have been doing so with magical assistance.
With over one million copies in print, Trudi Canavan has taken the fantasy world by storm. If you haven't done so already, The Ambassador's Mission is the perfect opportunity to discover the magic of Trudi Canavan.