~Luigi receives a letter from Princess Peach. Peach's Castle. Mario and Luigi leave their house. Mario and Luigi in Toad Town. Mario and Luigi arrive at Peach's castle. Mario and Luigi Inside Need a Key is the first Trouble Center mission in Paper Mario: The Thousand Year Door, initiated by Garf. Along with five other missions, it is first available after visiting Petal Meadows for the first time. after which the Trouble Center becomes accessible. Mission Mario must visit Garf outside his house east of Rogueport.