This is how our heroes go back to Traverse Town in Ryan's Quest.
They went to see Leon
Leon: So. You found the Keyhole?
Ryan: Yeah. And the Keyblade locked it automatic.
Sunset: Every world amount the Star has a Keyhole. And each one leads to the heart of that world. There must be one in this town as well.
Ryan: What does that mean?
Aerith: It was in Ansem's Report.
Tino: The Heartless enter through the Keyhole and do something to the world's core.
Ryan: What's happen to the world?
Sunset: In the end, it disappears.
Leon: And that's why your Keyblade is so important.
Aerith.: Please seal all the Keyhole. You're the only one who can.
Ryan: I don't know...
Leon: Seeing other world would probably serve you well..
Sci-Ryan: We gotta find your friends! And Optimus!
Ryan: I guess you're right... Okay! Hey, Leon. This Crystal is different from the others. Do you know what it's for?
Aerith: You should go see Cid. He should know.
Leon: And even though. Take this with you.
He give him a summoning gem
Leon: This stone holds some mysterious power. I've been carrying it for luck. I want you to hold onto it.
Ryan: It's Emmet who gave me this Gem. But... How do you use it?
They left to see Cid
Cid: What you got there? Well, I'll be. If it wasn't a Crystal.
Ryan: Yes. What's this one for?
Cid: You don't know? You're flying the Train and you don't know nothing about a navigation Crystal? Bunch of heroes. Interspace ain't no playground.
Ryan: That's a lot we don't know. So why? We have to use the galaxy train to go to other worlds. We don't have a choice.
Cid: Easy, Robot human kid. I didn't know. No hard feelings, all right? Well, I guess I could lend you a hand, then.
Ryan: Thank you.
Cid: Basically, with navigation Crystal, you can go to new places. You want one on your train, right?
They nod means Yes
Cid: I'll install it for you. But I got this thing I gotta go deliver first.
Ryan: What do you need to deliver?
Cid: Just this Book. It's real old. When that man brought it in, it was practically falling apart. Too broken to restored it to the way it was. But overall, I did a decent job puttin' it back together. Anyway, you mind delivering for me? It's the old house past the Third District. Look for a big fire sign.
He gave them a Brown old Book then they heard a noise
Ryan: Wh-what was that?
Cid: Hmm? The bell at the gizmo shop is Ringing. Go check it out if you want but deliver that book for me first. When you're done, stop by the house in the third District. I'll be there.
They went to third District and went to that House
Meg: There's something weird about this musty place.
Ryan saw Meg
Meg: It reminds me about the secret place, back at home, where we scribble on the wall. Remember?
Ryan look at his friends and he saw Meg gone
Merlin: Well, well. You arrived sooner then I expected.
They saw Merlin
Evil Ryan: My mentor.
Ryan: You knew we were coming?
Merlin: Of course.
Ryan: Are you a Heartless?
Crash: He don't look like one.
Merlin: Oh, my, no! My name is Merlin! I am Evil Ryan's mentor. As you can see, I am a sorcerer. I spend much of my time traveling. It's good to be home. Your friend request me.
Merlin: Yes, indeed. And who might you be?
Ryan: I'm Ryan.
Merlin: Ah, so, you have found the key.
Evil Ryan: What did Optimus ask you to do?
Merlin: Just a Moment. Presto!
He bring out his furniture and everything has been set
Merlin: There, Now, Ahem. Optimus asked me to train you in the art of magic. We can start anytime you like. Let me know when you’re ready to begin the training. Oh and one more thing.
Fairy Godmother: Hello. I’m the Fairy Godmother. Your friend asked me to help, too. I will assist throughout your journey.
Merlin: I do not know how much I can be of help, but do stop by anytime.
Ryan give him the book
Merlin: Oh, that book... So, Cid asked you to bring this. Thank you. You wish to know what kind of book it is? I don’t even know, myself. In fact, it’s not mine. Somehow it found its way into my bag one day. It was such a curious book, I asked Cid to repair it for me. Well, I guess I’ll put it here somewhere, for now. This book holds a great secret. The missing pages will unlock it.
He put it here
Merlin: I’ll leave the book over there. Do look at it whenever you like. My best regards to Cid for repairing it for me. Oh, and about that stone of yours... You should ask the Fairy Godmother about that.
Ryan: Do you know what this is?
Fairy Godmother: Oh, the poor thing! They have turned into a summon gem.
Ryan: A summon gem?
Fairy Godmother: Those little creature lived in a world that was consumed by darkness. When a world vanishes, so do its inhabitants. But this one has such a strong heart, they became a gem instead of vanishing with their world.
Ryan: Can they regain themselves?
Fairy Godmother: Yes, but only his spirit. Now, watch!
She use her magic
Fairy Godmother: Bibbidi-bobbidi-boo!
She make it magical
Fairy Godmother: Whenever you call, they will help you. If you find any more of these, bring them to me. Don’t worry, when their worlds are restored they will return there. Ryan, please help save them.
Ryan: Don’t worry, I will
They left Merlin House and they saw Heartless and then someone stop them and it was Cody
Cody: Hey, brother. Where were you?
He pull his hair
Cody: Hey, watch the hair!
Ryan: I'm not dreaming, am I?
Cody: No. It took me long time to find you.
Ryan: Cody! Hey, wait? Where's Meg?
Cody: Isn't she with you?
Ryan look sad
Cody: Well, don't worry. I'm sure she made it off our world, too. We're finally free. Hey, she might be even be looking for us now.
Then a Heartless appeared behind him
Cody: We'll all be together soon. But don't worry, just leave everything to me. I know this...
Ryan defeated the Heartless
Ryan: Leave it to who?
Cody: Ryan, what did you—
Ryan: I’ve been looking for you and Meg, too, with their help.
Cody: Who are they?
Evil Ryan: Ahem. My name is—
Ryan: We’ve visited so many places and worlds, looking for you.
Cody: Really? Well, what do you know? I never would have guessed.
Sonata: Oh, and guess what? Ryan's the Keyblade master.
Crash: Who would’ve thought it?
Ryan: What’s that mean?
Riku: So, this is called a Keyblade?
He's holding Ryan's Keyblade
Ryan: What! Hey, give it back.
He give it to Ryan
Ryan: Okay, so you’re coming with us, right? We’ve got this awesome train. Wait ‘til you see it!
Crash: No, he can’t come!
Craah: Forget it!
Ryan: Oh, come on! He’s my brother!
Crash: I don’t care!
Sci-Ryan: Huh? He’s gone.
Ryan: Cody? Nice going, Crash. Well, at least he's okay, and who know, maybe we'll ran into Meg, soon.
He saw Cody gone
They went to see Leon and the other
Cid: You guys ever heard of Kaos?
Ryan: No? But, who's Kaos?
Cid: I heard he's in town.
Ryan: Who's he?
Cid: Evil, man. He's evil!
Leon: He’s the reason this town is full of Heartless. Don’t take him lightly.
Aerith: He’s been using the Heartless for years.
Leon: We lost our world, thanks to him.
Cid: One day, a swarm of Heartless took over our world!
Leon: That was nine years ago.
Cid: I got out of that mess and came here with these guys.
Evil Anna: That's awful!
Leon: Our ruler was a wise man named Ansem. He dedicated his life to studying the Heartless.
Cid: His report should tell us how to get rid of the Heartless.
Ryan: Where’s this report?
Leon: We don’t know. It got scattered when our world was destroyed.
Cid: I’m sure Kaos’ got them.
Kaos and Cody are watching them outside
Kaos: You see? It’s just as I told you. While you running away trying to find your friend, he quite simply replaced you with some new companions. Evidently, now he values them far more than he does your. Now you’re better off without that stupid robot boy. Now, think no more of him and come with me. I’ll help you find what you’re searching for...
Cid: So, you delivered that book? That navigation Crystal has been installed and ready to go. You find another one, you bring it to me. I threw in a warp crystal for the heck of it. Now you can jump to worlds you’ve been to before. Well, better get back to my real job. What’s my real job? You’ll see. See me at the First District.
Aerith: I’ve been thinking about the bell in the Second District.
Ryan: That one that rang a bit ago?
Yuffie: The one above the gizmo shop. There’s a legend about it, you know.
Aerith: But it’s all boarded up. Nobody can get in there.
Cid: Heck, go check it out. Ring it three times to see if anything happens.
They rang the bell three times and they saw a Keyhole and then Guard Armor appeared
Ryan: Not you again!
They are fighting it and then it change into an Opposite Armor
Ryan: Aw man, I don't know how I fight you like that?
They are fighting and they defeated it, Ryan seal the Keyhole and got a Summon Gem
Ryan: I got that one down. Let's go see Cid.
They went to see him
Cid: Hey, now that was quick! Now you know. I’m in the Crystals business. Workin’ on your Train sure was great. Come again and I’ll give you a big discount.
He give them all the Crystals
Cid: Go ahead, take it. It’s a special giveaway.
They show him another Navigation Crystal
Cid: Hey, got another navigation gummi there, eh? I’ll bet you want it installed.
Cid: Hmm... Looks like this is another one of those crystal that come in sets. You got to find the mate to this one.
They left Traverse Town and head to Agrabah