Inside the portal, Mario hears Peach scream and sees some purple fog carry her off. Swim around to the portal using (A) to follow them. A voice says, "This place... divides... the real... and the dream." A pink bubble appears, saying, "You are now... entering... the dream world... Help... Help me..." Swim through the portal. Mario enters a brick building. Peach calls for him as the purple fog carries her off. Go to the right. The fog carries Peach farther to the right. Jump up the platforms, then take the moving platform to the left, where you'll find Broque Monsieur. He says to tilt the Circle Pad up to enter doorways. Go through the doorway, as you can't reach the area where Peach was taken.
Broque Monsieur is in the next area and will help you if you get lost. There are three more doorways and an item block to the right. The second door from the left leads to an item block with a nut. The second door from the right leads to two more doors below. From there, enter the middle door and Luigi appears. Mario pauses, then freaks out. Broque Monsieur warps down and Mario explains that Luigi is asleep in the real world. Luigi talks in his sleep while Starlow hovers around. Broque Monsieur says that this is Luigi, but not the real one. This one is how Luigi sees himself in the dream world, Dreamy Luigi. There are a few subtle changes to Dreamy Luigi, in that he is taller and a bit more handsome. His mustache has also improved, making him a dreamboat. Dreamy Luigi will help Mario. Broque Monsieur warps out of the area and the bros hug, making the real Luigi laugh. The other two doors that haven't been explored warp between the top and bottom floors. When you're ready, go to the right, through the door.
There's a Save Block ahead. Go to the right. The fog grows eyes and carries Peach farther to the right. The doorway leads to a shop run by Broque Monsieur. When you're done there, return and hit the orange ! Block. This makes a wall become a platform and releases a Dromba. Dreamy Luigi warps into Mario and Broque Monsieur appears. Dreamy Luigi now dwells within Mario, making him a little stronger. There are lots of Drombas to attack. Jump on a Dromba and many Dreamy Luigi duplicates, called Luiginoids, will drop down on other enemies. The Drombas will attack and the Circle Pad icon will appear, meaning Mario can move and jump. He can move in a line so he can counterattack more. If you move Mario in line with a line of enemies, he can stomp more of them. Luigi gains experience from dream world battles.
Broque Monsieur says the enemies only get stronger from here, so the bros must beat weaker enemies to defeat stronger ones. Jump up and go right. There are item blocks on the platforms above. Heal and save, then go right. The fog is ahead, still carrying Peach. It starts a battle. It creates a bunch of Marios for Mario to battle. They are called Dreamy Marios. They attack by dive-bombing Mario or running into him. When they run into him, if Mario stomps on them, they will dive-bomb him, so just jump over them. When you jump on them, one will remain. Keep an eye on that one to attack it. Sometimes the fog will send coins, Mushrooms, and fireballs at Mario. Use the Circle Pad to move to dodge fireballs and collect the items. The fireballs will cause Mario to lose coins. Sometimes the fog will carry Peach into the background and Mario will follow. Steer left and right, and jump to dodge the oncoming Marios. The fog will try to obscure your vision. If Mario's hit, he'll go back to battling Dreamy Marios.
After the Dreamy Marios are defeated, the fog will destroy the floor ahead, drag Peach down, then reform the floor. A light shines ahead, saying, "Keep going... You're so close... The nightmare chunk... Break it..." Go ahead to the right. The light appears behind a large purple chunk. Mario chips away at it by jumping. This reveals what looks like an orange pillow with a face. It says, "Ahhhhhhhh... I am at one with freedom. Are you the kind souls who set me free? I am in your debt. Thank you for freeing me. You want to know who I am? I see. You don't know who I am... INSOLENCE! Ahem... I am Prince Dreambert of the Pi'illo Kingdom. What? A princess was abducted? She's in the dream world? Hmmm... It seems some evil befell the real world in my absence... We must return to that world at once. Naught remains to do here. OK, are we ready?" The rock pillow starts sparkling and Mario returns via the portal.
Toadsworth asks about Peach. The rock pillow starts shaking and Luigi wakes up, closing the portal. The pillow turns into Prince Dreambert, this time, with a body. He introduces himself, shocking everyone in the room. Broque Monsieur said no one thought the treasured pillow was the prince himself, which explains why it was guarded. Prince Dreambert says his soul's essence was trapped within a chunk of solid nightmare. The bros set him free. Broque Monsieur thinks that the Pi'illo people may still exist and says that there are rocks shaped like pillows on the island. They may be other Pi'illo people. Dreambert takes off. Toadsworth thinks the fiend who kidnapped Peach may have something to do with Dreambert. Starlow says they should follow Dreambert.