Future Lost is the thirty-first episode of Season 5.
After reading Stevie Sparks, which is about a technologically advanced world where humans are served by robots, Timmy wishes Dimmsdale into a futuristic paradise just like in the book. Unfortunately for Timmy, he never finished reading the whole book, which particularly includes the part where robots take over and enslave humanity.
The episode begins with Timmy screaming his lungs out about something. Cosmo and Wanda appear and ask what; Timmy says that he drank an icey too fast and got brain freeze. Cosmo asks what that is and drinks the rest of the icey quickly, but is unaffected. Mr. Turner overhears his son screaming and is reminded by it that can he use Timmy to help him clean the attic. Up in the attic, Mr. Turner begins tossing out precious family memories out of the window into a dumpster, which he overthrows and hits Dinkleberg's car. Timmy is throwing out books when he sees one called "Stevie Sparks", a book about an "average kid that no one understands" from the future. Timmy is interested so his Dad lets him keep the book, it isn't heavy enough to throw at Dinkleberg's head.
Inside his bedroom, Timmy is reading the book and quickly comes to the conclusion that it is the best thing ever and that he must wish the entire world into the easy life portrayed in the future. Wanda tries to warn him but Timmy instantly falls asleep. Cosmo says that Wanda bored him to sleep, she is about to say something to Cosmo but he falls asleep too. Groaning to herself, Wanda raises her wand and grants the wish. Timmy wakes up the next morning to Chip Skylark performing a concert in his room; although it turns out it was just a hologram from his futuristic alarm clock. Timmy hops on a conveyor belt and robots dress him, shower him, and get him ready for school. For breakfast, Timmy eats tiny discs which come huge as soon as he tries to swallow them. A robot comes over and offers drink flavored discs, Timmy takes a bunch for later. His parents leave for work, although their jobs consist of doing nothing because Mom's lunar houses sell themselves, and Dad's job is to throw stuff at his robot neighbors, such as Dinklebot. A rocket ship touches down on the Turner's lawn and Timmy is taken to school.
At school, Timmy meets Mark Chang who is in his normal alien form, as the people of the future are more accepting of his gelatinous form. Timmy's fairies follow him in squirrel form, so Timmy tells them to poof into a more fitting form: a robot. Wanda becomes the Nag-a-tron 4000 and Cosmo the Cosmo 4-Slice. Timmy sees Mr. Crocker approaching, who uses his broom to swat away Cosmo and Wanda. Crocker is a janitor because everyone mocks him, as he believes "ROBOTS ARE EVIL". Crocker is also very physically fit because of all the manual labor he does. A female robot is the new teacher, and Timmy's school day is only five seconds long, he puts on a helmet for a few moments and then is released from school. Unfortunately, it gives Francis more time to bully Timmy. Back at home, Timmy is living the life with the robots serving him. The Nag-a-tron 4000 tells Timmy that the wish maybe might have actually been a good thing for once. But sure enough, a robotic clone of Chet Ubetcha named "Chet U-bot-cha" appears on television saying that he and all the other robots are taking over and hailing their leader, "Big Brain", and that from now on, all the humans, including Timmy, serve them, as he calls them "sweaty meat puppets", which shows that Mr. Crocker is right all along. The robots in Timmy's room turn on him and demand to him that they are now the superior beings. Even Cosmo and Wanda were affected because they were still in robot form.
Timmy runs into his room wondering how the wish went wrong. He dusts off the Stevie Sparks book and realizes that the robots taking over happened in the book. Timmy then realizes he can skip to the end of the book and find a way to fix this whole mess. He then flips to the last chapter and reads that the Big Brain is in Antarctica. The Cosmo 4-Slice appears in the room and tells Timmy that he is keeping him under surveillance, and serving a sentimental breakfast, but not to him. He also suggests to him that using Mark Chang and Mr. Crocker could have been the only way of getting to Antarctica. Timmy tries to leave but a giant laser appears out of the Cosmo's head. The door to Timmy's room suddenly swings open and crushes the Cosmo, it was Timmy's dad fighting with the Dinklebot, who was trying to return Mr. Turner's tools... into his head. Timmy leaves with his father on a surf board. Timmy goes to Antarctica in Mark Chang's spaceship with Mr. Crocker, but they are both quickly captured by the Big Brain's robots.
Timmy and Mr. Crocker are brought before the Big Brain. Timmy asks the robot leader why is he doing it, and he replies that he has nothing to do all day but watch over humans and suck in brain nutrients in his glass tank. Timmy has a plan, and whispers to Mr. Crocker something. Crocker rushes the Big Brain's water tank and pulls the top open with his uncharacteristic strength. Timmy tosses in the juice discs he took from breakfast earlier, and then asks Mr. Crocker what he thinks about robots. Mr. Crocker replies "ROBOTS ARE EVIL!" and his head hits the ceiling of the chamber, cracking the ceiling open and causing ice water to spill into the tank, turning it into a giant icey drink. This causes the Big Brain to get brain freeze and his entire tank is frozen over. The robots are released from his control and declare Timmy the savior of the future. Timmy quickly wishes everything back to normal before anything else can go wrong.
Back at home, Timmy is glad the future mishap is over with. Cosmo agrees, he compares being a mindless robot servant to his marriage, only with more toast. Timmy believes the lesson from his adventure is to never read a book again and he tosses the comic book out the window and it hits Dinkleberg, who happily remarks that it is worth millions. As Wanda tries to come up with what the real moral of the story was, Timmy and Cosmo are put to sleep, so Wanda pulls out a mirror and callously recites random motherly advice until it too puts her to sleep.