Sora's fourth stop in his mission is the Grid; upon arrival, Sora notices his clothes have changed and believes himself to be back in Space Paranoids. Just then, a Recognizer soars above him, and an excited Sora pursues it. However, aboard the Recognizer are two villainous programs who identify him as a stray, but he runs off.
Sora eventually makes it to the Bridge, where he runs across another masked program. As the two face off, they are unknowingly watched by three figures who are fascinated by Sora's Keyblade, one of whom identifies the masked program as Tron. Before they could fight, the masked program is contacted and runs off.
The figures approach Sora and introduce themselves as Kevin Flynn, his son Sam, and his confidante Quorra. When Sora compares the Grid to Space Paranoids, Flynn explains that the masked program, Rinzler, is Tron himself, having been corrupted by the Grid's despot, CLU. While Flynn and Sam are trying to escape the Grid, Sora is more concerned with saving Tron. Flynn realizes that if CLU had corrupted Tron, he most likely has Tron's source code.
Meanwhile, Rinzler returns to his master, CLU, and shows him footage of Sora and his Keyblade. Pleased with the results, CLU begins to have an idea.
With Quorra's help, Sora makes his way onto a Solar Sailer and sails to CLU's Throneship. However, they are unable to find Tron's source code, and Quorra tells him to look elsewhere. Before they could leave, Rinzler confronts the two. Sora attempts to jog Rinzler's memory, but Rinzler attacks and overpowers Quorra.
Just then the Mysterious Figure and Xemnas return. Xemnas explains that the Grid is the original version of Space Paranoids' data, and confronts Sora about the possibility of memories not even being one's own, especially Tron and Sora's. As Xemnas leaves, the Mysterious Figure reveals that since data cannot dream, then the Grid is very real.
Sora finds himself in the Disk Wars as "Combatant 13" and pitted against Rinzler. CLU finally meets Sora face-to-face and offers an ultimatum: if Sora offers his Keyblade, then CLU will restore Tron to normal. When Sora refuses, CLU orders Rinzler to take the Keyblade by force. Though Sora is unwilling to fight Rinzler, Quorra encourages him to do so, revealing that the Keyblade's power was able to get through to Tron.
Eventually, Sora is able to defeat Rinzler and restore Tron to normal. Enraged, CLU throws his disk to kill Sora, but Tron deflects the disk and it strikes the floor below him. As he falls, Tron reaches for Sora's hand, but fails. CLU leaves to reclaim Rinzler, and while Sora is saddened fron failing to save Tron, Quorra comforts him. After musing on Xemnas's words, Sora seals the Sleeping Keyhole.
Meanwhile at the Mysterious Tower, Mickey, Donald, and Goofy notice a raven fly in with a letter. The letter belongs to Maleficent, who has kidnapped Minnie. With that, Mickey, Donald, and Goofy set off to Disney Castle...
Tropes:
- Arc Villain: CLU, as in Tron: Legacy.
- Call-Back:
- Sora's outfit in the Grid is nearly identical to his outfit in Space Paranoids, just without the prongs on his visor. In fact, just before restoring Tron's source code, he briefly conjures this outfit.
- When restoring Tron's memories, Sora performs a variant of Tron's Complete Compilement Limit Break.
- Fallen Hero: Tron, who has become CLU's attack dog.
- Foreshadowing: Sora is listed as "Combatant 13." Guess what Xehanort has in store for him. Turns out this was completely accidental:
Rinzler was supposed to be a boss for Riku's side, and the "Combatant 13" moniker was pure coincidence. - Hero of Another Story: Sam and Kevin Flynn. As soon as Sora meets them, they disappear from the narrative to do their own thing and presumably follow Legacy's plotline while leaving Quorra to help Sora's mission.
- "I Know You're in There Somewhere" Fight: Sora attempts to talk to Rinzler and appeal to Tron within, but Rinzler doesn't listen. It isn't until the Disk Wars that Sora is forced to actually fight Rinzler.
- Late-Arrival Spoiler: Rinzler's real identity, Tron, was a complete surprise in Tron: Legacy. Here, it's stated almost as soon as Sora shows up in the Grid, and so he makes it his secondary mission to redeem Tron.
- Outside-Context Problem: While still normal enemies, the Nightmare Dream Eaters aren't the main problem in this world.
- Sequel Episode: To Sora's adventures in Space Paranoids. His secondary goal in the Grid is to redeem Tron.
- Stealth Pun: Sora has no idea where CLU is. He has no CLU.
