Paper Mario: The Thousand-Year Door
Princess Peach finds a map in an old town filled with crime. Mario sets off to the town of Rogueport, where he finds the Crystal Stars. There is a door deep in the sewers of Rogueport (the Thousand-Year Door) which will open if all the crystal stars are collected. It is said that a demonic spirit rests behind the door. The X-Nauts (a group of robot-like people) try to steal all of the crystal stars in order to awaken an evil demon to wipe out the planet so that they can become dictators of the world.