Mortal Folly

"Mortal Folly" is the 24th episode in season two of Adventure Time. Along with "Mortal Recoil" it forms a two-part episode.

Synopsis
When The Lich is accidentally freed from its prison in Princess Bubblegum's Castle, Finn and Jake must head forth to stop it from regaining its full power...all while being pestered by the Ice King to give him their blessing to marry Princess Bubblegum.

Plot
In Part One, Finn, Jake, and Princess Bubblegum are meditating on the balcony of the castle. At first the boys have trouble concentrating, but the princess tells them to clear their minds and it works. Finn has a vision of himself older and cooler with new powers such as having a mechanical arm. Jake has a vision of Lady Rainicorn riding a horse. Princess Bubblegum has a vision of a dark figure and panics. She says she needs to check on something and then the two decide to go with, so she gives Finn and Jake gems like the one in her tiara. They enter a secret room in the heart of the tallest tree where she shows them an ancient evil sorcerer called The Lich King (or The Lich) held in a prison of amber, and explains that the gems will keep themselves safe from the Lich's spells that control and possess people. Then she tells the story of how he plotted to destroy Ooo and kill everyone until The Hero Billy pushed him into the resin of the amber. As she explains, however, the Waving Snail climbs out of Finn's backpack and is quickly possessed by the Lich for not wearing the jewelery. The Snail makes a crack in the amber, and the Lich is quickly freed. When Finn and Jake try to stop him, the Lich escapes and heads towards the skies. Princess Bubblegum then takes them to the other secret room and gives Finn The Gauntlet of the Hero Billy, a gauntlet that Billy used to defeat the Lich the first time, and tells him to smite the Lich with it before he gets to his Well of Power and gets his magic back. She also tells Finn that the Lich's lair is cold so she gives him a sweater that she made, telling him she cares for him. As one last parting the trio hugs each other for good luck.

While they're hugging, a latched window opens up revealing the Ice King who butts in, asking Finn and Jake to bless his wedding with Princess Bubblegum, which of course they refuse to do. As they journey to find the Lich, the Ice King repeatedly begs for the blessing. After Finn uses the gauntlet on him, the Ice King gives up on the blessing and kidnaps the princess while she is eating ice cream in hopes that Finn and Jake are alright. All the while, Finn and Jake are in pursuit of the Lich, following the destruction he has left behind. As they reach the end of Iceberg Lake, just as Finn prepares to smite the Lich with the gauntlet, the Ice King interrupts them yet again to show them he kidnapped PB. While he does this, the Lich makes it to his well releasing hundreds of evil souls from the entry, so Finn and Jake hurry down, and the Ice King follows. Finn manages to fight off the Skeletal Guards that try to block his path, but his pack is ripped to bits while fighting. After blowing a hole in the ground with the gauntlet, Finn manages to grab hold of a hanging pipe leaking toxic waste, which forms the Lich's Well of Power in the chamber below, where The Lich begins his power rejuvenation. Finn tries to smite the undead creature with his gauntlet, but the Lich, having regained some of his old power, grabs hold of Finn's wrist and turns the gauntlet to dust, burning Finn's hand in the process. With their main weapon destroyed, Jake tries to 'bark' the villain, but is struck in the face with fire and knocked out, and when he falls, Finn's protective jewelry breaks and the Lich successfully possesses Finn's body in an instant. The Lich compels Finn to walk into the Well of burning toxic waste, asking him if he is cold, but Finn resists his influence by screaming, "I HAVE A SWEATER ON!!!". The Lich, having failed to take control of Finn's body completely, decides to destroy him with his flames, but they too fail to kill him. Finn realizes then that the sweater Princess Bubblegum made for him is keeping him safe, for it has the power of love in it, but Finn feels embarrassed saying love so he says "Liking someone a lot". Finn fully escapes the Lich's possession, and charges at him with his sweater, jumps on him and pulls the sweater through his eye sockets. As the Lich struggles, trying to burn Finn while laughing hysterically, Finn pulls the sweater vigorously upwards until the Lich's face is broken off and his body turns to dust. After Jake makes sure Finn is okay, the Ice King, in celebrating the victory he had no part in, decides to set PB free, but in doing so, he idiotically drops her into the boiling well, much to Finn and Jake's horror.

Major Characters

 * Finn
 * Jake
 * Princess Bubblegum
 * Ice King
 * The Lich
 * Snail

Minor Characters

 * Skeletal Guards
 * Boyfriend & Girlfriend Skeletons
 * Billy (mentioned only)
 * Princesses
 * Lady Rainicorn (in Jake's thoughts)

Trivia

 * This episode was previously titled "This Mortal Folly" and is listed as such in AT&T U-Verses' description of the the episode as well as on iTunes.
 * This is the first episode that begins a two-part episode.
 * Although the The Gauntlet of the Hero Billy the same as one used by Billy, Finn's appears to be right-handed while Billy's was left handed. It is possible that both gauntlets are part of a pair.
 * The Gauntlet of the Hero Billy appears to have 6 fingers instead of 5.
 * The animatic is here.
 * Although Finn was shown to cut all of his hair for the Tree Witch in "To Cut a Woman's Hair", this episode reveals it has somewhat grown back.
 * This is the first episode the Snail has a major role in, but the second where it interacts with the main characters, the first of which being "Storytelling".
 * Iceberg Lake from "Business Time" returns as Finn and Jake pursue The Lich, also confirming it as the location of the Gauntlet Dock which still hangs over the lake.
 * When the Ice King first appears in this episode, he says "Hey hey hey." the same way from the 80's sitcom What's Happening.
 * This episode and "Mortal Recoil" are the first episodes to reunite voice actors Ron Perlman and Hynden Walch since Teen Titans.
 * Ice King was in the Lich's lair without the protection of Princess Bubblegum's gems. However according to Adam Muto, one of the magic gems in his crown protected him from the Lich's powers.
 * It appears that when Finn is meditating, a picture of future Finn (or just Finn's hope of what he'll look like in the future) who has blonde locks exposed like Fionna from his hat that covers his one eye, bionic arm, huge muscles, and Spiked Ice Club or what looks like a sword with a Spiked Ice Sphere on the handle.