Lisa had just dragged the family into going into another boring trip, this time to the science invention contest. Inside Lisa starts talking how interesting everything is. Then Lisa runs off. Homer sits down on a chair to sleep. Marge says to Bart can you watch Maggie while I find Lisa. Ok Bart says. He walks around with Maggie in his arms. He sees a virtual reality machine and puts Maggie on the ground and tries it.
When he is dome he can't find Maggie. He spots Maggie going into what looks like a port-a- potty so he goes in to get her without knowing the door closes and Homer being dumb as it is pulls a lever to see what happens. This is dumb he thinks and leaves. Bart comes out with maggie in his arms what happened he says as he leaves. Dr. Fink comes and says this is his age modifier. That it will make one person 1 year younger randomly while the other becomes 1 year older randomly and it wont stop unless you go back in to either turn back or stop the process.
Bart wakes up the next day to find out that his PJs seem a little big today. His pants almost cover his feet and his sleeves covers his hands. Bart goes downstairs to eat still in his PJs and tells Marge that his he got smaller over night. Marge says sorta of the same thing. Maggie grew over night and is it just me or she looks a little older. She was right she did look a little older. And you Bart Marge says you look younger. That is ridiculous Bart says. Just then Bart shrunk even more and he is the same size as lisa and he barely fits and Maggie grows more that her clothes tear. Lisa notice that Bart has a more childish looking face and maggie looks like a 4 yr old. Lisa says Bart is getting younger and Maggie is getting older by one year. Oh my pore baby marge says while hugging Bart, Bart says possibly soon I will be a baby. Bart you are staying home today we don't want you shrink more in class Marge says. Alright Bart says.
Lisa gets home from school to see what looks like a 7 year old Maggie on the floor watching TV with what looks like Bart as a 5 yr old on the couch. Marge comes in and tells Lisa that it got worse. She also said that she gave Maggie her old clothes and Bart his old clothes. Why couldn't you go to Dr Hibert. I tried but he was on Vacation. Later that night Maggie was Bart's original age while Bart was Maggie's original age wearing his old clothes for when he was 2 sitting in Maggie's high chair. I don't want to sit in here Bart says in toddlerish voice. Marge places Bart in maggie's room while Maggie slept in Bart's.
The next day things got worse Bart now a 1 yr old and Maggie a 11 yr old. Maggie sat that at the contest her and Maggie entered a machine and that probably did this. Lisa says just in luck the contest is still today. They rush to the contest, by the time they got there Bart was new born. We don't have much time. They go to Dr. Frink and tell him happened. Quick put them in the chamber. Bart started glowing quickly before he disappears. Do you want them to stay the same or change them back. Lets keep them this age so we can raise Bart to be a good boy. Dr. Frink pushes bottoms and pulls a lever and Maggie is in new clothes while Bart is wearing clothes a new born would wear. There they will age normally. Maggie will have full memory of what happened but since Bart got to young he will not have any memory of what happened in the past. On the way home they buy Maggie and Bart new clothes and stuff. Then Lisa all of a sudden looks older while Homer looks younger. Marge says"Lisa did you go in the Machine while we weren't looking. Yes Lisa says, but this will stop at a certain age not like Bart and Maggie, they didn't know is that you can have a age limit so no one would die or be unborn. The simpsons drove home with their new baby version of Bart, new 12 year old version of Maggie, a 25 yr old Lisa and a 8 yr old Homer. I hope we will never see that Machine ever again. As they drove by nelson and Millhouse have the Machine and they re-enter it saying millhouse will age while Nelson will de age.