Expansion pack Mask of the Betrayer picks up from the moment D&D-loyal RPG NWN2 finished, with the King of Shadows defeated, and your character squished beneath a collapsed building. You're alive, but there's something wrong. You're now at the bottom of a dangerous dungeon, with only a suspicious Red Wizard for company. Up and at 'em.
Fear not if you haven't completed NWN2: you can fire right in with a brand-new level 18 character, which gives you the chance to try out the six new sub-races (Wild Elf, Half-Drow, and Air, Earth, Fire and Water Genasi), and two new classes (Favoured Soul - similar to the cleric, but with more divine power, and Spirit Shaman - a master of the spirit world). And the deific tone of these new classes is no coincidence. MotB is all about religion.