During a heatwave, an experiment freezes over Kauaʻi.
In the midst of the hottest day of the year, Lilo and Stitch retreat to the air-conditioned airport to take photos of tourists. Stitch tries to buy a soda from the vending machine, but it eats his dollar. He begins shaking the vending machine and an experiment pod falls out into a storm drain. Unbeknownst to the duo, An ominous glow emits as the storm drain freezes over...
Gantu complains about the ship's air conditioning being out as the computer announces the activation of 523, an experiment that can freeze anything at will. Meanwhile, 523 hitches a ride on a helicopter and blows his icy breath all over the entire island, causing it to snow. Stitch is scared of the snownote so Lilo has to drag him home. As they arrive, Jumba sees the snow and concludes that it must be the work of 523, warning that unless stopped, the blizzard will continue forever.
Stitch hesitantly joins Lilo on a journey to the peak of Mount Waialeale, where 523 is thought to be breathing his ice breath from. However, 523 gets the drop on them and freezes Stitch solid, leaving Lilo defenseless. Just then, Gantu fires a net and captures 523. Lilo picks up Stitch's ray gun and blasts him out of the ice, and Stitch knocks Gantu off a cliff as the duo bring 523 home.
The snow on the island quickly melts, as 523 (now named Slushy) is safely inside a containment pod. Lilo decides to play in the snow with Jumba and Pleakley and uses Slushy to snowify the area immediately surrounding her house. She tries to convince Stitch that playing in the snow is fun, but he is reluctant to try new things. After some convincing, he joins the others in ice-skating and sledding. Unfortunately, no one was keeping track of Slushy and Gantu took him while everyone was preoccupied.
Gantu uses Slushy to create a giant ice fortress in order to transform the island into a colder climate similar to his home planet. His plan is to use his thermal detector to locate the remaining experiment pods, while no one else will be able to find them in the snow. Lilo and Stitch approach his fortress and make snowmen decoys before ringing the doorbell. Gantu destroys the snowmen with his blaster, but the real Lilo and Stitch take the opportunity to sneak inside. They are quickly encaged by some of Slushy's icicles, and Gantu mocks them for trying to stop his plans. However, they were just the distraction all along, as Jumba and Pleakley burst in with Splodyhead (X-619).
Splodyhead fights Slushy's ice breath with his plasma spit, and the two seem evenly matched in a long battle until Splodyhead blasts the ice palace itself, bringing it down on top of Slushy. Slushy uses the icy rubble to his advantage, as it appears he can move the ice boulders with his mind. Splodyhead is frozen solid and Stitch takes the initiative. Slushy shoots snowballs at him, but he catches them and throws them back, knocking Slushy down and stunning him.
With the battle now over and Gantu having surrendered, Stitch breaks Splodyhead out of the ice so he can thaw the island by shooting plasma balls into the sky. Slushy's one true place is making snow cones at the local shave ice shop. As Stitch eats a snow cone, Lilo remarks that even though Stitch didn't want to try new things, she's glad he gave snow a chance.
Experiments who appeared or were mentioned in this episode:
- Slushy (X-523): This episode's Monster of the Week; an icy blue koala-like experiment who can freeze things around him, causing it to snow on the island.
- Splodyhead (X-619): Helps stop Slushy when things get out of hand.
- Reuben (X-625): When Gantu gets a cold after his defeat, he makes food and takes care of him.
Tropes featured in this episode include:
- An Aesop: Never be afraid to try new things.
- Aside Glance: Pleakley mistakes the snow for invading aliens before being corrected. Stitch does this as Pleakley tries to backpedal, claiming he was only joking and as the expert on Earth, "of course" he knew about snow.
- Chekhov's Gunman: Splodyhead is seen early on in the episode getting a cooling adjustment from Jumba to prevent from overheating during Kauaʻi's heatwave. He ends up being instrumental in stopping Slushy during the episode's climax.
- Elemental Rivalry: Slushy and Splodyhead have an epic battle of fire and ice.
- "Eureka!" Moment: When Pleakley asks Lilo how she intends to stop the "little freezer burn" (Slushy), it gives Lilo the idea to bring in Slushy's natural opposite: the fire-shooting Splodyhead.
- Exactly What I Aimed At: Lilo seemingly fires a plasma gun at Gantu, only to miss. Turns out, she was actually aiming at a frozen-solid Stitch to thaw him out.
- Glacial Apocalypse: Despite Jumba's initially beliefs that he didn't have a lot of evil potential, Slushy is actually capable of bringing about a second ice age for all of Kauaʻi. Gantu’s Evil Plan of course, is to freeze the entire island because only he’d be able to find the experiment pods.
- Godzilla Threshold: The grand scale of Slushy’s power required the heroes to bring in the destructive, fire-based Splodyhead to contain Slushy.
- Gone Horribly Right: Played With. Throughout the episode, Jumba constantly said that he considered Slushy one of his least evil experiments due to not believing there was any threat in making things icy cold. After Slushy ends up in Gantu's possession and starts freezing over everything, Jumba finally recognizes Slushy's potential as the entire island was at risk of being turned into a frozen tundra, causing Jumba to let out an Evil Laugh as he realized Slushy was very evil after all.
- Only One Finds It Fun: When Jumba lets out an Evil Laugh upon the realization that Slushy could freeze the entire island into a solid chunk of ice, he finds Lilo and Stitch giving him a blank look.Jumba: Oh, right. Not big fans of evil. (Sheepish chuckle) Sorry.
- Out-of-Character Moment: Lilo turns down shave ice shop owner Luki's offer to give Stitch a mixed-flavor shave ice, telling him that Stitch doesn't like to try new things (playing into the aesop of the episode). So Stitch, who is well-known for his massive appetite, would not like to have a frozen dessert just because it's a different flavor?
- Pass the Popcorn: Just before Slushy and Splodyhead go into an elemental clash, Jumba moans that he left his camera at home.
- Series Continuity Error:
- Stitch initially does not enjoy the snow at first in this episode. But the ending montage of the original film shows a photograph of him having clearly enjoyed the snow with Lilo, Nani, and David before on a snow-covered mountain somewhere.
- Splodyhead is misnumbered 515 (Deforestator's number) by Jumba in this episode.
- Why Don't You Just Shoot Him?: Gantu finally decides to blast Lilo and Stitch into smithereens. Unfortunately, they were just snowmen dressed to look like the duo.
