Dib summons Mortos der Soulstealer, a mystical being who emerges once every thousand years, in order to wish for him to steal ZIM's soul. However, when it turns out that Mortos needs to recharge his power before he can complete the task that Dib requested, Dib must help him do many absurd things in hopes of putting an end to ZIM once and for all. Meanwhile, ZIM heads around town undergoing his latest evil scheme, which is the reason Dib was so eager to enlist Mortos' help in the first place.