This is they came back to Hill Valley and find the Time Machine in Ryan's Quest 2.
[They are back in Hill Valley and they saw Marty picking up all the Parts]
Marty: Hey, guys.
Sora: What are you doing.
Marty: Picking up for Doc's Inventions. Doc's need those.
Ryan: And aren't you supposed to be in School?
Marty: Already did. Now, help me.
They carried all the Parts for Doc and they went back to his house
Doc: Where did you find them?
Marty: Around Hill Valley.
Doc: I see. But those are the Part for my Time Machine that has been stolen.
Sora: What!? The Parts from Time Machine?
Marty: It has been Stolen!?
Doc: Yes. Someone who took it from me, while I was sleeping.
Ryan: Who took it?
Doc: Don't know, but we have to find the Culprit.
Marty: Then let's go find him.
They went off and they found the Delorean from Xigbar
Xigbar: Uh oh!
Doc: So you are the one who took my Time Machine!
Ryan: Give it back to him!
Xigbar: As if, but how about this?
He summon a Giant Nobodies,they are fighting it and they defeated it
Xigbar: Good job, and bye!
Doc: Who was he?
Ryan: A Member of the Organization 13, we have to find their Stronghold and stop them.
Marty: Hope you will.
Sora: Don't worry, we stop them no matter what.
Doc: And, Ryan? About your brother. You will find him. Trust me. It's my vow.
They left this world