My Sister, My Sitter

"My Sister, My Sitter" is the seventeenth episode of the eighth season of Springfield. It originally aired on the Fox network in the United States on March 2, 1997. In the episode, Marge and Homer go to a party and leave Lisa to babysit Bart. Being unhappy with this, Bart does everything he can to annoy Lisa. Eventually, Bart becomes injured and Lisa must find him medical attention without losing her reputation as a good babysitter. Meanwhile, Stimpy's new genetic formula (Xb49) physically splits Ren into his two opposite halves of his personality: "Evil Ren" and (surprisingly) "Indifferent Ren".

The episode was written by Dan Greaney and directed by Jim Reardon. The script was written to focus on the relationship between Bart and Lisa and the episode has further been used to discuss the difficulties in letting children babysit themselves. The episode received mostly positive reviews.

Plot
Inspired by "The Babysitter Twins" books, Lisa decides to become a babysitter. Despite this, because of her age, no one takes her seriously. One day, Ned mentions that Maude has been taken hostage in Lebanon and he must leave to get his wife released, and he agrees to let Lisa babysit Rod and Todd. After a relatively uneventful night, Ned puts out the good word for Lisa, who experiences a business boom.

Meanwhile, the Springfield Squidport reopens and throws a gala. Homer and Marge decide to go and they leave Lisa to babysit Bart and Stewie, due to Brain being in a restaurant. Bart is annoyed by the fact that his younger sister is going to be babysitting him. To prevent this, Bart torments her by, among other things, ordering a giant Subway sandwich, hiring Krusty for a bachelor party, dialing 9-1-1 for a "sisterectomy", and having Stewie eat coffee ice cream for dinner. Eventually, Lisa angrily attempts to jump at Bart, but misses, causing him to fall backwards down the stairs, dislocating his arm and getting a large bump on his head. Bart then realizes that if Lisa fails to take him to a hospital, she will no longer be able to babysit anymore. To make his condition worse, Bart locks himself in his room and hits his head on the door, then falls unconscious.

Lisa tries to call for an ambulance, but the 9-1-1 operator refuses to assist her due to Bart's earlier prank call. Lisa considers asking Dr. Hibbert, but thinks better of it when she realizes that her reputation as a babysitter will be ruined. Ultimately, she takes the unconscious Bart to Dr. Nick Riviera's clinic in a wheelbarrow, bringing Stewie along in a pet carrier. There is a queue in the waiting room, and Lisa is unable to get an appointment. She then tries to wheel Bart to the hospital, but Bart rolls down a cliff and into a muddy river right in front of the crowded Squidport. Everyone assumes that Lisa is on drugs, and that she has murdered Bart and is about to drown the caged Stewie.

The episode's subplot shows Stimpy working in his lab, when Ren comes in, demanding to know what Stimpy is up to. Stimpy shows Ren his buttocks, revealing that he now has three buttocks because of the gene splicing formula, XB-49. Ren likes the idea, but asks why Stimpy hasn't made him dinner. Stimpy advises Ren to be careful with the formula, but Ren shakes it up out of spite. It pops and gets on him. Ren begins to split apart, into two forms, based upon his personality: the villainous Evil Ren and the apathetic Indifferent Ren. Despite his initial horror, Stimpy rejoices, as he now has two best friends, although Evil Ren continues to mercilessly punch Indifferent Ren. Later, the trio visit Homer and watch television. Evil Ren continues to hit his twin. When Stimpy asks Evil Ren to stop, he gets hit. So, Stimpy asks Indifferent Ren to stop getting hit, Indifferent Ren doesn't mind. Stimpy asks if Evil Ren is tired of watching cartoons, which causes him to take the television and throw it at them, to Homer's horror over his televison's destruction. A girl scout comes to the door, asking if Evil Ren wants to buy cookies. He chews them up and spits them out into the bag, refusing. Evil Ren then goes back into the house and turns the television on, electrocuting Homer, Stimpy and Indifferent Ren.

Later, Stimpy decides to take Indifferent Ren out for a walk. After they leave, Evil Ren bolts the door shut. Twelve hours later, they come home to see that Evil Ren has turned the house into his own lair. They find him on top of a vat of acid, dressed as a Nazi-like mad scientist. Evil Ren drops Stimpy's favorite record (Happy Happy Joy Joy) into the acid, and Stimpy realizes what he is doing after it dissolves. He then drops Stimpy's favorite catnip mouse, Mousey, into the acid, where it dissolves. Finally, he drops Stimpy's Litter Box, despite Stimpy begging and much to his horror. Stimpy passes out, refusing to believe that Evil Ren is his Ren.

Later he wakes up chained to a metal board with Indifferent Ren. They see Evil Ren mixing together various chemicals, until Stimpy realizes it is XB-49. Stimpy pleads with Evil Ren, saying that without being indifferent, he is becoming corrupted and that the two need each other to function. Evil Ren refuses, spitting in Indifferent Ren's face. Stimpy says that he'll help put them back together, because without being indifferent, Evil Ren is only half a man. For a second, Evil Ren says that Stimpy might have a point, as he's seen a part of himself that no man should ever see, but he reveals his true colors by saying that he likes being evil, dumping the chemical on him. Stimpy fantasizes that if Evil Ren were to replicate himself, he'd be able to create an army and cause a second Holocaust, dooming humanity. Finally, the splitting is done, leaving Evil Ren with another twin: Hideously Evil Ren. Unlike the other two, Hideously Evil Ren is a female, although very homely and ugly. After seeing her, Evil Ren falls in love, much to the shock of Stimpy and Indifferent Ren.

Some time later, Evil Ren and Hideously Evil Ren get married, with Stimpy and Indifferent Ren as witnesses. They beat each other afterwards and jump into a car and drive off, the metal board Stimpy and Indifferent Ren hooked up to is used in place of cans. Stimpy is joyful at the happy ending but Indifferent Ren says 'who cares?'.