Mortal Recoil

"Mortal Recoil" is the twenty-fifth episode in season two of Adventure Time. This is half of the two-part season finale along with "Mortal Folly".

Synopsis
Though the Lich appears stopped, an accident by the Ice King has lead to Princess Bubblegum becoming slightly altered, leading to an unlikely final showdown with one of the greatest evils in order to save all life in Ooo.

Plot
In the previous episode, Princess Bubblegum was dropped in a toxic pool that served as a source for the Lich's powers. The episode opens with Dr. Ice Cream, Nurse Poundcake and Doctor Princess with other candy hospital staff trying to save princess bubblegum from her affliction which is diagnosed as being "totally gross on 90% of her body and the other 10% is crazy nasty." The Ice King is present and expresses concern about her being ugly for "their marriage" before Finn punches him. The doctors try to stabilize her condition and are eventually succesful after a brief flatline, returning her to her normal state, albeit with a sickly grey skin color. Princess Bubblegum tells them all she needs is some rest. The Ice King is happy but the citizens call him old and express their disdain for him. He comes to a realization about his unpopularity and flies away. Finn and Jake attend the princess in her bed chamber as she rests. She exhibits strange behavior including spasms, heavy breathing, convulsions and crawling into the bathroom. Finn returns her to her bed and takes some time to confide his feelings to her, asking Jake to leave the room. Finn thanks her for the sweater she made him and tells her that they should discuss their feelings later but she is unresponsive. Princess Bubblegum then asks Finn to bring her several things, left unknown to the audience. Jake returns with Peppermint Butler who, upon seeing PB whispering to Finn, freaks out and hisses at her, then scampers out of the room. Finn leaves to find the things the Princess requested. Jake remarks that the happenings recently are weird and decides to play music for the princess who places her hand inside her room's flower decorations, killing and withering all of them. Her eyes turn green and she starts speaking in angry jibberish. Jake plays a different song and the Princess summons magical fire into the room and scares Jake who runs out of the room as Finn returns to the hall outside. Finn has an assortment of items which he reveals are things like gasoline, turpentine, plutonium and other hazardous chemicals. Jake urges Finn to not bring the chemicals to Princess Bubblegum but she opens the door and takes them from Finn and returns to her room. Jake tells Finn of the fire she summoned and this alarms him. Finn and Jake then enter the room where Finn believes PB is just having private time in the bathroom. Jake looks through the keyhole and forces a relunctant Finn to as well. They see Princess Bubblegum, now with a demonic form, pouring the chemicals into her bathtub, forming a pool like the one the Lich used for his power. She starts drinking the liquid but before Finn and Jake can stop her she rips the bathtub from the floor and pours it all into her mouth as she enlarges in size. Finn tries to convince her to stop drinking, but she smacks them through a wall where the Ice King is walking by and she starts attacking the kingdom. The Ice King confesses that he saw the Lich possess Princess Bubblegum immediately after the original accident because he has magical wizard eyes that let him see supernatural things. He offers to help the duo in the fight but Finn denies him, still blaming the Ice King for PB's condition. Jake tells Finn they could use his Ice Powers and freeze the monster but they proceed without him anyway. Finn readies the sweater the Princess gave him and Jake launches him at the monster but his attempt fails when she simply punches him out of the air and back into the castle and through a wall. Finn swallows his pride and prejudice and asks the Ice King to help in the fight. Finn distracts the monster while the Ice King freezes her from the feet up. The monster is stopped and everyone rejoices, but shortly after, it tips over and breaks apart on the ground having had unstable footing when it was frozen. In an effort to save Princess Bubblegum again, the doctors rush her to the hospital and try and put her back together from the remains of the monster. The heroes and candy people wait outside the operating room before a nurse comes out and says that she is fine, but there were complications. She confides that there wasn't enough bubblegum to put the Princess back together, making her smaller and thusly become thirteen-years-old. The new princess enters, looking younger and shorter and Finn remarks that he is thirteen as well. The Ice King loses interest in the young PB before him and leaves. The princess approaches Finn and they share a loving embrace as everyone rejoices. The episode ends with the scene panning out to the window, where the Lich-posessed snail is waving menacingly.

Major Characters

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

Minor Characters

 * Peppermint Butler
 * Raggedy Princess
 * Dr. Ice Cream
 * Nurse Poundcake
 * Doctor Princess
 * Candy People
 * Cinnamon Bun
 * Emerald Princess
 * Wildberry Princess
 * Lumpy Space Princess
 * Guardians of the Royal Promise
 * Snail

Trivia

 * This episode and "Mortal Folly" would have been the final episodes of the season prior to the rescheduling of "Heat Signature". The two-part episode is still considered the season two finale by the show's crew.
 * This is the first time Finn directly states he's 13 years old, although this was already known from the events of "Mystery Train" and from statements made by the show's crew.
 * This is the first time the Snail is shown in the titlecard and/or in the final shot of the episode.
 * Young Princess Bubblegum was voiced by Isabella Acres.
 * In the emergency room at the start of the episode, the heart monitor screen is displaying the first 15 digits of pi.
 * When PB was possessed by The Lich, she spoke with a deeper voice, her skin was pale and sometimes contorted; this could make reference to the 1973 horror movie The Exorcist.
 * This episode uses a background music from Dragon Ball GT