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. 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 the Lich King returning and panics. Deciding to check on him, she gives Finn and Jake special jewelry to protect their minds from the Lich, who uses spells to control people's minds and bodies. They enter the secret room where she keeps him frozen in amber, and explains how he plotted to destroy Ooo until Billy pushed him into the resin. As she explains, however, the Waving Snail climbs out of Finn's backpack and is quickly possesed by the Lich for not wearing the jewlery. 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 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 gives him a sweater that she made, telling him she cares for him.

Just before they leave, the Ice King 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. 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, 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 and arrives to see the Lich beginning his power rejuvenation. Finn tries to smite the undead creature with his gauntlet, but The Lich easily crushes it. Jake attacks the villain, but is knocked out, and when he falls, Finn's protective jewelry breaks and the Lich tries to control him. He can't, however, because of Finn's love sweater. Finn tries to kill him with the sweater and seemingly does. When he vanishes, the Ice King decides to set PB free, but in doing so, idiotically drops her into the boiling well.

Major Characters

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

Minor Characters

 * Skeletons
 * Boyfriend & Girlfriend Skeletons
 * Lady Rainicorn (Cameo in Jake's thoughts)
 * Snail

Trivia

 * This is the first episode that begins a two-part episode.
 * A special trailer for the two part episode aired on April 25.
 * Although the The Gauntlet of the Hero Billy is 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 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.
 * It's shown that Princess Bubblegum wears magic jeweled earrings which can be made into headbands that, like her crown, can protect their wearer's minds from the Lich's influence.
 * This is the first episode the Snail has a major role in, but the second where it interacts with the main characters, which was in "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.
 * This the first Rebecca Sugar episode to not have a song in it.
 * It is shown that Princess Bubblegum is a nervous eater, as she unknowingly ate a candy person when she was hoping Finn and Jake were O.K.
 * More proof of the post apocalptic world is seen when Finn and Jake go to the Lich's lair. It is an abandoned subway tunnel, you can see the subway cars and tracks laying everywhere. Also, when Finn and Jake enter the ruined subway tunnel, the skeletons came alive, it is possible these skeletons were Humans before they died, a big clue is that some of the skeletons were dressed in work clothes, which indicates that the skeletons (humans) could have died while getting on a train.
 * 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.
 * Princess Bubblegum wears earrings, though she does not appear to have ears.