. Climb the stairs and pull the rope for the doorbell 3x to get an Elixir
. Now proceed to the lab entry door and go up the stairs. The professor will say he needs some memory and tells you to go find Sally. When you regain control, check the bookshelf to get a Torn Page
. Jack will also join you here.
Exit the place and there'll be a cut-scene between Jack and the mayor saying that something went wrong, so now you'll have to get rid of those previously harmless Heartless. Proceed to the Graveyard. There will be a swarm of enemies for you to kill. When they're all dead, there will be a cut-scene with Sally. She'll give the forget-me-not item which is the memory. Take it back to the lab. There will be a cut-scene.
The professor will ask you to find one last ingredient, the "surprise". There will be a cut-scene with Oogie Boogie. Go back to the graveyard and jump in the coffin. Now you have to check the tombstones. Look at the order in which the ghosts rise and examine the tombstones in that order. The big pumpkin will open up and the treasure chest will contain a jack-in-the-box. Take it back to the professor.
After the cut-scene you'll need to find those kids. Go to the graveyard again and there'll be another cut-scene. Go to where the open pumpkin was and examine the door. Inside explore the new area and you will find that there is a platform to be lit. Light it with your fire magic. Next go up the long pole and examine the structure that is sticking out of it. You'll be taken to a new area so go to the far left and light the platform. Cross the bridge and there will be a long cut-scene.
In this new area walk up the bridge and examine the door. Once inside there will be a red trinity mark and a treasure chest containing an Ether
. Light the lantern in that room. Jump on the platform. Your only way here is up, so keep going until you find the Playroom. Here you'll find Lock, Shock and Barrel and they'll fight you. There isn't much strategy in this battle so just beat them up. Try talking to one of them and they'll accidentally tell you about the lever. So examine the machine on the side to find it. There's also a save point here. Save before leaving.
It's time to find the "green door". Just fall off the ledge and try landing on the grayish-black path to find the Torture Chamber. Go in. You'll see a cut-scene where Boogie swallows the heart and attempts to summon some Heartless. You'll fight him after that.
Boss Battle - Oogie Boogie
There is no way you'll be able to reach him by just jumping so don't bother. Let your partners handle the Heartless he had summoned. Make sure you keep the target lock on Boogie all the time so that you'll know where he is. Now when the small panels around the platform starts glowing, step on the one that is located directly across from where he is. This will make a portion of the platform rise to Boogie's level giving you the opportunity to hit him. He'll push you off after a while, so just wait for the panels to glow again.
He will also drop some explosive dice at you, so make sure you keep an eye on that. Watch out for the spinning blades too as those can be pretty deadly. This can no doubt be an annoying battle so just keep your cool and you'll win eventually.
The battle isn't over yet. Oogie Boogie has now grown to an enormous size. I strongly recommend that you go back to the Guillotine Gate and save before you fight.
Boss Battle - Giant Oogie Boogie
You have to find and destroy all 7 orbs. Cast Aero on yourself first just in case you fail to dodge the flames. There will also be some Heartless here but it's best to let your partners handle them. You can deflect the fire balls that come out from Oogie Boogie's lanterns, using Sora's Guard ability. (if you have it) You'll receive 49 Tech Points for each successful attempt.
You'll get the Gravira upgrade. After a short cut-scene Jack will give you the Pumpkinhead
key chain, then you're free to go. But be sure to go back to where Giant Oogie once was for a chest with a Dispel-G
When you get to Halloween Town there will be a cut-scene. Never mind the Heartless here, they won't hurt you. When you regain control, go north then west into the small gate. Get the chest here for