Dr. Finkelstein is working on his Experiment in Halloween Town, but he can't seem to get it right. While trying to figure out what to do next, he is suddenly attacked by an unseen force. Once Sora, Donald, and Goofy arrive, they see Jack picking up Christmas presents in the forest. He says that he's going to return the presents, which somehow appeared in the forest, back to Santa. When they get to Christmas Town, Santa tells them that lots of presents were stolen, and he entrusts Jack with the task of finding the culprit.
In the factory, they find Lock, Shock, and Barrel, who claim that they didn't steal the presents, but they run around anyway. After catching the three hooligans, they still swear they didn't do it, and instead they say they were looking for parts for the Experiment on behalf of Finkelstein. Sally comes in and tells them that more Heartless have appeared in the town square; what's more, they're messing with some more presents. They begin to think that the Heartless are the culprits, so they destroy them and recover the presents. Finkelstein tells them that the Experiment has been stolen. They assume that the Heartless did it, but Finkelstein says that whatever the culprit was, it wasn't the Heartless.
Jack comes up with an idea: make some decoy Christmas presents to lure the thief into a trap. Santa reluctantly agrees to let them make the presents, and they enter the factory to make some. They take the presents to a plaza beside Santa's workshop and hide inside the boxes. When the culprit arrives, they jump out only to see that Finkelstein's Experiment is the thief. They fight and destroy it, and Santa thanks Jack by letting him ride in his sleigh.
Back in Halloween Town, Sally says that the Experiment probably stole presents because it thought those could help it obtain a heart, since Christmas presents are a way to give your heart to someone you care about. Santa creates snow in Halloween Town and leaves. Jack and Sally have a romantic dance, which makes Sora think of himself and Kairi. After bidding farewell, the trio leaves Halloween Town for their next destination...
- Arc Villain: Dr. Finkelstein's Experiment
- Christmas Episode: The events are set on Christmas Eve, although Santa didn't show urgency in retrieving the stolen presents.
- Comically Missing the Point: When one of the presents is ruined by the Heartless, Jack laments how nice the box was, while standing on the doll that was the actual present. Sora tries to point this out, but Dr. Finkelstein interrupts him.
- The Dog Was the Mastermind: The present thief is Dr. Finkelstein's Experiment, who sought to acquire a heart.
- Foreshadowing: The Experiment trying to obtain a heart will become more relevant during the events of Dream Drop Distance.
- Mistaken for Thief: SDG caught Jack in Halloween Town holding presents and wearing his Santa suit, making them think he stole them from Santa in yet another attempt of taking over Christmas. Jack just found them as they showed up, and was wearing the outfit to mark Christmas, but they don't believe him and hand him over to Santa.
- Mystery Episode: The theme of the episode. Several presents along with Dr. Finkelstein's Experiment have been stolen, and it's up to the party to find out who the thief is and stop them. The thief is the Experiment itself.
- Never My Fault: Dr. Finkelstein refuses to take responsibility of the Experiment's failure, blaming Lock, Shock, and Barrel for bringing him faulty parts (and tossing them) and decides to find new assistants. Of course, the Experiment turns out to be a success. A huge success.
- Not Me This Time: Three groups of suspects are indicated on stealing the presents.
- Once again, Jack has to effectively clear his name due to Santa and Sora suspecting him of stealing presents in another bid to take over Christmas.
- Lock, Shock, and Barrel were caught inside Santa's workshop going through the toys. They were just looking for parts for the Experiment, and don't care for the toys as they're not scary or gross.
- Several Heartless were spotted playing with toys in the Halloween Town square, and Jack suspects it was them who stole the presents. Since they act on instinct, there's no plausible reason why they could've stolen presents, and no one in Halloween Town or Christmas Town reported sightings of Organization XIII, clearing them as well.
- Schmuck Bait: Invoked. Jack has several large boxes disguised as presents with himself and SDG inside the largest one. The plan is to wait for the thief to arrive and take the bait so the party could catch them in the act.
- Ship Tease: Sora's romantic feelings for Kairi are pretty clearly spelled out when he sees Jack and Sally have a romantic moment, and ultimately imagining dancing with her. Donald and Goofy also immediately pick up that Sora is musing about getting Kairi a gift and encourage him.
- You Have GOT to Be Kidding Me!: Sora has this reaction to seeing Jack holding presents while wearing his Santa suit, accusing them of being a thief.Sora: You just happen to find them!?
