From Floors 2 to 6, Sora can choose to visit Wonderland, Olympus Coliseum, Agrabah, Monstro, and Halloween Town in any order. This is assuming he's visiting them in the order he does in the first game.
The next illusionary world Sora, Donald, and Goofy find themselves in is Wonderland, where the White Rabbit is once again rushing to the castle of the Queen of Hearts, fearful of her punishment. They decide to follow him, arriving at the court. Once again, Alice is being put on trial. This time, however, the charges are different. Unlike the real Queen of Hearts, this one knows about the Heartless, and she accuses Alice of helping them and stealing her memory. The White Rabbit explains that they can't get rid of the Heartless without the queen's memories. Of course, Alice denies involvement in the crime, and Sora rushes to her defense. When the Queen of Hearts asks Sora who the real culprit is, he says that he stole her memory in order to protect Alice. The queen sends out her Card Soldiers once again. Sora manages to hold them off long enough to give Alice a chance to escape, but there are too many of them, so the trio is forced to flee the castle.
Back in the Lotus Forest, they catch up with Alice. Sora explains that he was lying about being the thief, and Alice thanks him. The Cheshire Cat suddenly appears and says that the queen won't leave them alone until they recover her memory. Sora considers just leaving the queen alone, but Jiminy points out that if they don't do anything, she'll have Alice's head, so he decides to help. The Cheshire Cat warns Sora that his memories may lie to him before disappearing.
The group find themselves in the Bizarre Room, where the Queen of Hearts and her soldiers reappear. The queen tries to sentence them to execution, but she suddenly forgets where she is and what she is doing. Suddenly, the memory thief reveals itself: the Trickmaster, the same giant Heartless they fought in the real Wonderland. Sora defeats it, but then the queen tries to have her soldiers attack again. Alice tells the queen that she ordered them to destroy the Heartless to prove themselves to her. She questions it at first, but when Alice asks her if she remembers, the queen snaps that she never forgets anything. Unwilling to admit that she may have forgotten anything, the queen acts as though they're telling the truth and compliments their abilities. Alice tells Sora that she remembered what the Cheshire Cat said about one's memories lying to oneself, and she used that and the queen's ego to get them out of a tough situation. Sora thinks about the Cheshire Cat's words and looks concerned about something, but he keeps it to himself. Goofy then forgets the truth as well, saying that the queen commanded them to destroy the Heartless. With that, the trio leaves Wonderland.
Back in Castle Oblivion, Goofy says that he's been thinking about what he said earlier, about the castle they explored during their previous journey (Hollow Bastion). He says that it couldn't have been his imagination, because he remembers that the castle is where Sora used Ansem's Keyblade to give Kairi her heart back. Goofy continues to reminisce about when Sora vanished, and he wonders how he forgot about all that. Sora recalls turning into a Heartless, but he can't remember it happening in a castle. Donald claims to remember the castle, but he can't name it, so he asks Jiminy to look in his journal. The cricket pulls it out, but to his shock, the journal is completely empty. As they wonder what happened to it, we see the white room where someone is drawing again, this time seeing that the person drawing is a blond girl.
Now on the next floor, Sora wonders aloud if they could be losing their memories somehow. Jiminy reminds them what the cloaked figure said about having to lose something in order to find what they're searching for. He considers the possibility that their memories are the thing they have to lose. Sora realizes that they must be losing more memories the farther up they go through Castle Oblivion. Sora wonders if he'll forget about Riku and Kairi, but Goofy assures him that they'll never forget their friends. As Donald doubts Goofy's words, Goofy points out that Sora never forgot him and Donald even as a Heartless, so the castle shouldn't have the ability to make them forget their friends. Sora teases Donald about attacking him in his Heartless form, and the trio continues onward, feeling assured that they won't forget their most important memories...
