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.