Luigi’s Escape and the Third Heart Pillar
After the end of the second chapter, the action changes again to Schloss Knickwitz. This time you take control of Luigi for the first time.
Run to the left and walk through the next door. Keep yourself further and further to the left in the following rooms and use every door that lies on your path. Enemies or puzzles do not expect you during this short section.
After several rooms, Luigi reaches a dead end. The following cutscene ends his escape attempt and the action moves back to Mario and Princess Peach.
You are now back on the Flipside Tower. After talking to Merlon, you must bring the third Pure Heart to his Heart Pillar.
Use the elevator on the left and drive down to the second level of Flipside. Save your score on the nearby Save Block if necessary.
Run near Merlon’s house and switch to 3D view with Mario. To the right of the building, you can see the gate that you opened after the first chapter with Merlon’s Old Key.
Go through the gate and stay in the third dimension first. A narrow path leads right out of the normal screen level. Follow this web to the end and switch back to the 2D view.
Continue to the right until you reach the green warp pipe. Jump in and you’ll get back to the outskirts of Flipside.
Follow the path completely to the left this time. On the way, you will pass the place where Princess Peach has inserted the orange Pure Heart into the second Heart Pillar. Continue running until you discover a green warp pipe on the left end, which is blocked by several stone blocks.
Attention: In this outskirts there is more than one blocked warp pipe. For the way to the third Heart Pillar you need the warp pipe on the far left.
Equip Boomer and set him down next to the stone blocks. Explode him to destroy the blockade. Then jump into the exposed warp pipe.
You land one level deeper in the underground outskirts of Flipside. Run to the right and defeat or bypass the opponents on the way. At the right end, a high wall seems to stop your progress.
Switch to the 3D view. Laterally in the wall you can now see an extremely narrow gap. Mario alone does not fit through even in the third dimension.
Select the Pixl Slim and activate its ability. Mario turns to the side and becomes paper thin. Align it exactly to the gap and run through the narrow opening to the other side of the wall.
Deactivates Slim and switches back to the 2D view. In front of you is the third Heart Pillar. Approach and use the yellow Pure Heart you received from Merlee.
On the Flipside Tower, a new yellow door appears. It leads to the Bitlande and thus to the third chapter.
You can now walk all the way back through the Warp Pipe and across the outskirts. However, it is much faster with the retreat tube from your inventory. Use them to return directly to Flipside Tower.
Save it again. To the right of the doors to Chapter 1 and Chapter 2 is now the third, yellow door. Go through to begin chapter 3-1: The Bitlands.