Matt's World is a mission pack which takes place in an alternative timeline after Saints Row: The Third. It features the return of the Decker's leader Matt Miller who arrives back in town for revenge against the 3rd Street Saints.
Taking place after the Kill Killbane ending in Saints Row: The Third the Syndicate has collapsed and the Saints are back to complete power. A year after those events a vengeful Matt Miller returns and captures the Saints, placing them into a simulation nicknamed 'Matt's World' which is heavily inspired by the Nyte Blayde Universe.
The Saints find themselves pitted against creatures such as Vampires and Dragons and must escape Miller's game and stop him once and for all.