In the Realm of Darkness, Riku and Mickey are on their search for Aqua. Riku reminisces on his previous trip there as well as the promise he made to Terra. He and Mickey reach the Dark Margin, where Mickey says that Aqua's trail is gone. He figures that she is deeper in the darkness, but they aren't adequately prepared to go further. A bunch of Shadows appear and merge together into a Demon Tower. They defeat it, but another one appears and swallows Riku. In the darkness, he hears a voice call out to him. When he wakes up, his hair is shorter, and he finds that his Keyblade is broken. Realizing that they're no match for the Heartless there at the moment, they decide to leave and return later. Before they do, Riku leaves his broken Keyblade in the sand, saying he'll leave it for the "other him."
Sora, Donald, and Goofy return to the Mysterious Tower shortly before Riku and Mickey do. They tell the trio about their failure in the Realm of Darkness. Riku wonders if they can find someone who has a strong enough connection to Aqua to locate her, but everyone close to her is gone. Riku and Mickey decide to visit some of the worlds Aqua did to find clues as to her location. Yen Sid gives them some new outfits to give to Kairi and Lea as well as Sora. Yen Sid tells him that in addition to his new outfit, there is also a "gift" from Chip and Dale. Before they leave, he gives Sora one more thing: an item called a Heartbinder that allows him to summon allies to aid him. Yen Sid says "May your hearts be your guiding key" before sending them off.
Back on the Gummi Ship, Sora, now in his new outfit, receives a call on a device he's never seen before. He answers it to find Chip and Dale, who explain that their gift to him was a phone they call a Gummiphone. They tell him about the data they got from Ansem the Wise from Riku before. Sora then gets a new call from Ienzo, formerly Zexion of the original Organization XIII. He is in Ansem the Wise's computer room in Radiant Garden with Aeleus, the Somebody of Lexaeus and a guard of the castle. Ienzo explains that they were manipulated by Xehanort, and now that they know the truth, they want to help Sora instead. He tells Sora that the data revealed the presence of another heart inside him, which doesn't surprise him. Sora assumes that the heart inside him is Roxas. After the call ends, Sora decides to head to Twilight Town due to its connection with Roxas. With that, the trio's journey can really begin in earnest... thus (for real this time) begins the plot of Kingdom Hearts III.
Tropes:
- Brick Joke: In the intro (and, by extension, 0.2), Goofy mentions that he's always heard Yen Sid say "May your heart be your guiding key" at the end of his speeches to the trio, but Sora and Donald don't believe him. So they're quick to listen closely during his new speech, and sure enough, he whispers it.
- That Came Out Wrong: Mickey says that Aqua is like Sora. Riku, having assumed her to be a composed, intelligent Keyblade Master, is quick to assume that means she's just as impulsive as Sora is before Mickey clarifies he means she's strong like Sora.
- Wrecked Weapon: The Way to the Dawn is snapped in half during the fight with the Demon Tower.
