When her most loyal friend is taken hostage by Peregus Malister, the cruel master of the Thieves Guild, Marek must embark on a corrupt mission to serve the Thieves Guild with her team of would-be heroes. But when the mission leads them into the clutches of Szorlok - their greatest enemy - Marek must sacrifice her ambitions, and perhaps her own soul, to stop Szorlok from obtaining the Darkspore and to save her friends.