"Frost & Fire" is the thirtieth episode in the fifth season of Adventure Time. It is the one hundred and thirty-fourth episode overall.
A fight between Ice King and Flame Princess causes Finn to have a premonition dream. Finn becomes obsessed with the dream and wants to find out how it ends so he asks Jake for advice. Jake tells him to make Flame Princess and Ice King fight again.
Finn and Flame Princess are hanging out outside of the Tree Fort. Finn hands her a log, which she burns in her arms. Suddenly, the two are interrupted by Ice King, who was flying by overhead. He taunts Flame Princess for hugging a log. Finn groans and feebly reaches at the Ice King. Flame Princess supersedes Finn's attempt to help, and flies toward the Ice King herself, beginning a fight. She punches him in the stomach and sets his underwear on fire before kicking him back into the Ice Kingdom. Her aerobatics produce a fiery heart shape in the sky, and she flies back to Finn, who blushes in his astonishment.
Night falls, and Finn falls asleep in his bed. He starts to dream. Clouds of smoke surround Finn, and he asks "What's cooking? Smells good!" He looks around in confusion and realizes that he is on fire, and begins to scream and panic. However, he soon sees that it is Flame Princess burning him below his stomach. He then realizes it feels good and starts laughing. In the background, a disembodied voice whispers something indecipherable.
Finn awakens to Jake talking to himself as he makes eggs. Finn runs to him, explaining that he had an amazing dream. He tells Jake his dream and mentions that he assumes it was inspired by Flame Princess and Ice King's battle. Jake responds by rambling on about his own elaborate dream. During Jake's narration, Finn begins daydreaming, and decides he must make Ice King and Flame Princess battle again to trigger his dream.
Finn invites Flame Princess out for a picnic in the Ice Kingdom. Whilst sitting, the two the see the Ice King flying home with his groceries, innocently whistling. The Ice King overhears Finn's call and shouts out a friendly greeting. Finn then misleads Flame Princess into thinking that the Ice King was actually making fun of her in the tone of his voice. Flame Princess becomes enraged and confronts the Ice King. Ice King panics and tells her that she can take anything she wants from him. He throws his groceries at her, which hurt her because they are frozen, and she punches him with full force.
Thrown to the ground, Ice King spawns four snow warriors, three of which promptly fall apart. Flame Princess forces the Ice King into submission, while explaining why she hates being made fun of. Just as Flame Princess is about to beat up on the Ice King, the last of his snow warriors bear hugs Flame Princess, freezing her. She falls in pain. Ice King laughs victoriously and flies away. Finn runs to Flame Princess' aid, and she assures him that she will be fine.
Night falls again, and after some bizarre sleeping rituals in the Tree Fort, Finn falls asleep. His second dream begins with the same opening line as his first: "What's cooking? Smells good!" However, this time Finn looks down to discover the Ice King hurling ice cubes at him instead. Finn panics and then sees the Cosmic Owl laughing at him, and recognizes his voice as the incomprehensible whisper from the first dream.
Finn awakens screaming, and hurries downstairs to explain his dream to Jake. Jake freaks out at Finn's mention of the Cosmic Owl, saying that his presence means Finn's dream was prophetic, and that Finn must finish the dream to understand what the Cosmic Owl was saying. Finn rapidly writes an insulting, belligerent letter to Ice King while pretending to be Flame Princess, and another letter to Flame Princess while pretending to be Ice King. Finn delivers the letters, and the two enraged recipients meet in the Ice Kingdom for an epic show-down while Finn spectates from a snow trench.
The fight escalates into a huge explosion, causing the Flame Princess to burn up and enlarge into 'Flame Mode', destroying a large part of the Ice Kingdom in the process. Ice King retaliates by controlling his Ice Mountain like a giant warrior, but is quickly destroyed. The snow then begins to melt, and the Penguins flee. Finn admits to himself that he has gone too far, and collapses in the overwhelming heat, entering his third and final dream.
Finn sits in his bed, and as in his first dream, Flame Princess sets him ablaze. However, this time she completely burns his body, transforming him into a hairy, manly baby repeating the word 'wah'. Flame Princess is startled by this change and walks away. The Cosmic Owl stands before him, and Finn finally makes out what he was saying: "You blew it."
Finn awakens to Flame Princess's destruction of the Ice Kingdom. He runs into the ice cave and rescues Gunter and Ice King. Because Finn is carrying the Ice King on his back, Flame Princess mistakes him for the Ice King, and hurls a flame ball towards them. Ice King freezes the fire blast, saving them.
When Flame Princess realizes her mistake, she shrinks out of ‘Flame Mode' and apologizes. Finn explains that he is the one who is sorry. He explains that he has been manipulating Flame Princess and Ice King into fighting, and admits that he was the one who forged the letters. Flame Princess feels betrayed, especially because the things in Finn mentioned in her letter were so personal to them as a couple. She ignores his apology (just hearing the 'wah' shown in Finn's dream) and tells him that she needs some time alone. As she walks away into the sunset, the Ice King tells Finn, "You blew it, man."
- We learn a variety of Flame Princess's abilities in this episode:
- She has the ability to hover.
- She can shoot beams of fire from the center of the gem on her forehead.
- The Ice King has the ability to control his mountain.
- Flame Princess's forged letter to the Ice King reads:
- Dear Ice King,
- You smell like stink. You're unpleasant, you're not funny, you're old, and no princess will ever marry you ever, simple Simon
- Sincerely Love,
- Flame Princess
- P.S. Let us fight.
- Ice King's forged letter to Flame Princess reads:
- Dear Flame Princess,
- You're just the worst. Your hair is bad, your feet smell like face cheeks, your stupid candles smell heinous and you can't even kiss Finn without totes freakin' out!
- Let's meet up and fight, dummy.
- Ice King
- In Finn's first dream, the Cosmic Owl can be heard saying "You blew it" multiple times.
- Princess Bubblegum spoke a little German while seeing the fight between Ice King and Flame Princess. "Ach, mein Glob!" means "Oh, my Glob!"
- Ice King referring to Flame Princess holding a log ("You're hugging a log, you weirdo!") could be a reference to the Log Lady in the television series Twin Peaks, regarded as crazy by the other characters due to her habit of carrying a log in her arms.
- Flame Princess' attack in the last fight looked similar to Kamehameha, the signature attack of Goku, from the Dragon Ball manga and anime.
- Ice King's attack in the last fight looked similar to Big Bang Attack, the signature attack of Vegeta from Dragon Ball Z.
- In the last fight, Flame Princess and Ice King had a beam struggle, which may have been a refrence to the Kamehameha vs Galick Gun beam struggle from Dragon Ball Z.
- When Flame Princess grows into a giant, Ice King takes control of his mountain, and the two battle each other, this may be a reference to the Giant Boss Battles from Mario and Luigi: Dream Team.
- The scene where Flame Princess and Ice King engaged in a battle in the Ice Kingdom is reminiscent to the scene in Pokémon 2000 Movie where Articuno, Zapdos, and Moltres battle Lugia.
- This episode is the first of Finn and Flame princess' break-up arc (plus Princess Bubblegum's involvement). The next is "Too Old" and then "Earth & Water."
- This episode's title is similar to that of "Earth & Water." Both episodes are also about/feature Flame Princess, Finn, and somewhat Ice King and Princess Bubblegum.
- Princess Bubblegum can be heard saying "Ach, mein Glob!" which translates in English to "Oh, my Glob!". Princess Bubblegum has not spoken German since "Go With Me."
- The Cosmic Owl returns to deliver a Premonition Dream, something previously seen in "The New Frontier" and "The Lich".
- During the scene where Finn wakes up from his third and final dream, the music from "Burning Low" plays.
- Ice King's snow monsters fell apart like the Cuties army from "Conquest of Cuteness."
- The letter Finn sends to Flame Princess reads "your stupid candles smell heinous" is a reference to Flame Princess' scented candles from "Ignition Point". It also reads "and you can't even kiss Finn without totes freakin' out!", which is a callback to Flame Princess's Elemental Matrix, seen in "Burning Low".
- The letter Finn sends to the Ice King mentions his's old name from before he wore the crown (Simon). Finn learned it in "Holly Jolly Secrets Part II".
- In Finn's letter to the Ice King, Finn wrote that Ice King was unpleasant, but when Ice King read it, he never said that.
- The story is a surprisingly explicit reference to Finn's pubertal changes and developing sexuality. Finn is visibly aroused by Flame Princess' battles with the Ice King, even though he doesn't understand why. His dreams, in which Flame Princess shoots fire at his crotch and he enjoys the experience, are thinly veiled wet dreams.
- Finn's dreams seemed to work in a certain way: In the first fight, Flame Princess won, which caused Finn to have the dream about her, Ice King won in the second fight, in which Finn dreamt about him, and in the last battle, Flame Princess appears to prevail, and Finn dreamt about her again.
- In his third dream, Finn starts talking like the miniature version of himself in "All the Little People", and in the real events he sounded like this to Flame Princess after admitting to manipulating her.
- Finn speaking the Little People language likely represents that he did not truly learn a lesson from that episode about manipulating others' lives.
- Also in the third dream, Finn turns into a baby version of himself with facial hair and long, hairy legs. This likely represents both Finn's physical maturation (his puberty) and the immaturity of his actions in the episode.
- Finn used intimate details of Flame Princess (scented candles, the kiss) and Ice King (his real name) in his letters to them.
- Finn's choice of white noise for his "Sleep Jam" is odd. Though the sound of ocean waves is a common white noise, Finn has intense thalassophobia (seen in "Ocean of Fear"), most likely making the sound of waves a panic trigger for him.
This episode was censored in some countries. See Censorship of Adventure Time for more information.