Super Paper Mario/Chapter 3: The Bitlands

Rescuing Luigi
Using Luigi, keep going left and through doors until you hit a dead end. Natasia will come and brainwash Luigi.

Chapter 3-1: When Geeks Attack
Boss:Bowser

Chapter 3-2: Bloops Ahoy
Boss:The Big Blooper

Chapter 3-3: Up, Up, and a Tree
Boss:Dimento

Chapter 3-4: The Battle of Fort Francis
Boss:Francis