After being punished with no more television for ruining both his parents' jobs by using elements from a violent television show called "Maho Mushi", Timmy has had enough of tolerating his torturing babysitter Vicky. He wishes up for a magical remote that allows him to enter inside television shows; unfortunately, however, the remote falls into Vicky's hands. With the remote, Vicky (Whom The Bowser Family) plans to enter the biographical channel which is featuring "Dictator Week" so she can become a world dictator. Timmy wishes up for another magical remote, and enters (along with Winnie the Pooh, Piglet, Tigger, Rabbit and Eeyore) inside television in order to stop Vicky's plans. Meanwhile, Timmy's parents Mr. and Mrs. Turner, who dismiss their son's concerns of Vicky every time, refuse to believe that Vicky is most certainly an evil babysitter, until a fateful day when they receive information proving otherwise from Vicky's younger sister, Tootie.
20 years into the future, adults Chester and A.J. race through a dystopian Dimmsdale, chased by a masked man. The masked man pleads to Chester and A.J. to give up, but they believe it is a trap. Chester stays behind and tries to stall the masked man, but the masked man easily dispatches him and zaps him with a laser, freezing Chester in stasis. A.J. has gotten ahead, and managed to make it to his old house where he completes a time belt so that he can go into the past and prevent the bad future from ever happening. But before he can get do this, the masked man freezes A.J. and takes the belt from him. A robed figure appears behind him, who is revealed to be Vicky, now the Supreme Ruler of the World. She sends the masked man back in time to prevent Timmy from stopping her.
Back in the present, sixteen-year-old Vicky is preparing a backpack full of torture items for when she babysits Timmy, while a news editorial by Chet Ubetcha begins airing on the TV. He is warning adults about violent TV and how it is affecting kids. Chet particularly blames a program called Maho Mushi, a Japanese anime-type fighting show resembling Dragon Ball Z. Meanwhile, Timmy wishes for a Maho Mushi spaceship known as the Kid Crusher (a parody of The Star Destroyer from the Star Wars films) and flies it around Dimmsdale, raining destruction and causing widespread panic on the streets below. When he almost crashes into a plane, he wishes himself into a "Banzai Bubble" from his Maho Mushi cards and then starts plummeting toward his dad's office. Timmy destroys his dad's office and ruins his dad's chance to win a raise and a "Cleanest Office" plaque and upstage his archenemy (and neighbor) Dinkleberg. Elsewhere, Mrs. Turner is about to sell Billy Joel a glass house, when Timmy collides into it causing it to shatter, just moments before the transaction was to be completed. As Mr. and Mrs. Turner drag Timmy home to punish him, a green light and electrical sparks fill the alley, and the masked man from the future appears.
Meanwhile, at Timmy's house, Mr. and Mrs. Turner scold Timmy for mimicking a violent television program after they discovered that all of the violence that Timmy imitated was from Maho Mushi. Mr. and Mrs. Turner tell Timmy to not watch Maho Mushi anymore and watch an educational program instead, like Dictator Week (a parody of World War II history) on the Biographical Channel, but Timmy refuses. This makes Mr. and Mrs. Turner angry when they realize that they cannot trust Timmy to not mimic television, and therefore they cannot trust Timmy with television at all, and so they ground Timmy from watching television, and hire Vicky to watch him while they go out. Before Mr. and Mrs. Turner can leave, Timmy begs his parents not to leave him with Vicky, as she is evil. Mr. and Mrs. Turner briefly suspect something about Vicky, but they shrug it off after Vicky showers them with cheap gifts she got. Mr. and Mrs. Turner run off to gloat about their gifts to Dinkleberg. Timmy barricades his door behind him to prevent Vicky from coming in, and then sarcastically asks his fairy godparents what he should do now that his parents grounded him from watching television. They take the hint, and poof up Timmy a television so Timmy can watch television again. However, Wanda still scolds Timmy about disobeying his parents (even though they didn't listen to him about Vicky), so Timmy decides to wish himself a magic remote that gets him into the TV.
Timmy explores a few channels, first a cartoon show about the future called The Futurellis, then a cartoon program called Carpet Critters, and later a cartoon program called Heavy Hal. Cosmo and Wanda watch Timmy as he interacts with the TV programs he explores, when Vicky comes and tries to bust down Timmy's door. Cosmo disguises himself as Timmy and does a bad job at hiding the fact that Timmy is trying to sneak in and watch television again in his room. Vicky takes a photograph of "Timmy" next to the TV and decides to tell on Timmy. Outside of Timmy's house, the masked man is stalking Timmy. Mrs. Turner gets a call from Vicky, who says that Timmy not only immediately turned on the television after they left, but also caused a variety of other destructive events around the house that were really caused by Vicky herself. Mr. and Mrs. Turner furiously return home.
Back inside TV, Timmy is in another cartoon program called Jonny Hunt. Timmy is happy that the adults in that program will allow a 10-year-old boy like him to go on dangerous missions, but not without giving him a dangerous weapon first. Timmy returns to the real world and shows Cosmo and Wanda the rocket launcher he got from television. Wanda explains to Timmy that Fairy Godparents are only assigned to kids who need them most. When godchildren get older their fairy godparents are sent back to Fairy World and all memories of the fairies are forgotten by the godchild. This upsets Timmy when he realizes that he will one day forget all the adventures he had with Cosmo and Wanda. Vicky arrives with Timmy's parents. Timmy accidentally fires the rocket launcher he brought back from television, blowing the roof off and destroying the upper floor of his house with the roof landing on the masked man, who is standing on a tree, knocking him unconscious. This infuriates Mr. Turner to his peak as he can no longer take Dinkleberg getting all the awards and money. Timmy's parents give the magic remote to Vicky as punishment, and they threaten to ground Timmy harder for disobeying them and trashing the Turner household.
After his parents refuse to believe him again about the truth of Vicky's evil, Timmy decides to run away from home and live through television. He wishes for another magic remote and poofs into the TV with Cosmo and Wanda. The masked man, who was spying on them the whole time, follows them. The masked man ends up in the wrong channel showing a cartoon called Paula Poundcake. Meanwhile, Timmy and his fairies have arrived in Walnuts where Timmy plans to live here forever. After the adults call the police on Timmy, he decides to go into Space Spectre.
Back in the real world, Vicky is watching TV with the magic remote which inadvertently merges a political debate show called Politically Inaccurate with a wrestling show. She realizes that the remote is magic, and changes the channel to a contest show. Vicky accidentally switches places with the $1,000,000 winner with the magic remote. She is handed a bag of money, but the host takes it back when its pointed out that Vicky is 16, and too young to participate in the TV contest. Frustrated, Vicky smacks the remote again, pressing the fast forward button and aging herself to 18. Vicky is now able to take the contest money, and she also begins to realize the power of the remote. She wants to go to the Dictator Week program on TV and change history so that she can take over the world.
Still inside the Space Spectre cartoon, Timmy and his fairies are about to be captured by the masked man, who has tracked them down. The masked man demands the remote, promising that he will send Timmy back home unharmed, but Timmy refuses and manages to use his remote to escape the channel. His next destination is The Meatflints. The masked man continues to chase Timmy through other programs including Go Go Racer, Snooper Dog and the Clue Crew, and Blackbird and Sparrow. Back in Dimmsdale, Mr. and Mrs. Turner are looking for Timmy and start their search by questioning Chester and A.J. about Vicky, and whether she is really evil. Hidden cameras and shocking ankle bracelets prevent the two from telling Timmy's parents the truth. Meanwhile, in the Blackbird cartoon, Timmy is again attacked by the Masked Man. This time, Timmy manages to corner the masked man in the Birdcage and takes off his mask, and the man is revealed to be Timmy himself, from the future.
Adult Timmy reveals that Vicky successfully changed history and became Supreme Leader of the world, turning Dimmsdale into a desolate wasteland. Sneaking into the ranks of Vicky's troops, Adult Timmy managed to become Vicky's most trusted soldier. He was sent after Adult Chester and A.J. who were inventing a device to go back in time and stop Vicky. Once A.J. completed the device, Timmy took it so that Vicky would send him back in time with it and not suspect anything. Adult Timmy needs to stop Vicky and destroy the remotes so that the future will change. Present Timmy is unconcerned with this at first, but agrees to help after the group is attacked by Vicky.
Mr. and Mrs. Turner continue to look for answers. They go to Vicky's House and decide to talk to Vicky's dad and mom directly, but they are no help, when arrays of Lasers are on them. They are completely terrified of their daughter, and push Mr. and Mrs. Turner out of the house the moment they realize they might suspect something of her. Tootie is watching from her room above and overhears that Timmy is missing because of Vicky, and decides to take matters into her own hands. She throws a cryptic message attached to a Timmy doll through the window of the Turners' car, asking them to meet her at the Dimmadelphia Cable building, disguising her name as Deep Toot. In the TV universe, Timmy, Cosmo, Wanda, and Adult Timmy chase Vicky through some more programs, including Clint's Hints, Ted and Jimmy, Rabid Rabbit, an unnamed Christmas special, The Feldmans, and Poppyseed Avenue.
Mr. and Mrs. Turner meet Tootie in the parking lot of the Dimmadelphia Cable building. Tootie shows the Turner parents photographs of Vicky's misdeeds, including the ones they had blamed on Timmy. Mr. and Mrs. Turner learn that Timmy was right about Vicky being an evil babysitter. Before they can thank Deep Toot for her help, she disappears without a trace. They are completely bewildered to her identity, despite her mistakenly including her real name on her cryptic notes. Mr. and Mrs. Turner have realized their mistake and realize they should find Timmy and apologize to him, heading to the Dimmadome station. In television, Timmy is about to enter the next channel, Maho Mushi, riding on the credits of the previous show, Adolescent Genetically Altered Karate Cows. However, Vicky destroys Adult Timmy's time belt, sending him falling to his death and causing him to return to the future. Timmy becomes furious that Vicky took away the one cool adult in his life, just like she takes away everything else from him. He vows to defeat her, in Maho Mushi, once and for all.
At the climax, Timmy and Vicky enter Maho Mushi and appear in a fighting arena. They use the power of their remotes to battle each other, control giant fighting robots to battle each other, fire blasts from the remote, and use the remotes as glowing swords to attack each other. Battling to a stalemate, Timmy realizes the only way to defeat Vicky is to become old enough that Cosmo and Wanda's magic goes away, and the remotes will stop working. He ages himself all the way to age eighteen, and the remotes stop working. However, the Fairy Taxi arrives to take Cosmo and Wanda away. The fairies resist, so a tractor beam begins to suck them toward the taxi. Before it can get them both, the fairies make Timmy 10 years old again, so he gets to keep his fairies. Timmy gets both of the remotes back and recharges their power, using them to blast Vicky out of television and back into her room. She lands roughly in her bed, thinking it was all a dream. Timmy has finally won the battle as he, Cosmo and Wanda leave the program. Timmy is still worried that his parents are still mad at him for what he has done.
Back home, the Turners plead Doug Dimmadome for his help using the cable station to broadcast a message to Timmy, because they were sure that wherever he was, he was in front of a TV. As Doug Dimmadome debates with himself whether to help the Turners or have security remove them (since Timmy has both helped and foiled Doug Dimmadome in the past), the Turners sneak by him and use the studio cameras to broadcast a message to every channel on TV, apologizing to Timmy for not believing that Vicky is evil and told him that he must come home because they love him. Timmy sees the message while he is surfing through the TV Universe and decides that it is time to return home. When his parents finish the broadcast, he appears out of the TV, hugs them and reconcile.
Back at the Turner household, Mr. and Mrs. Turner finally confront Vicky for being a cruel babysitter and fire her. However, Timmy uses the remote to pause everything, and then wished the remotes never existed, and nobody to remember all of this happened. Timmy realizes that without Vicky around to make him miserable, he would lose his godparents. He wishes that everyone forgot all the events that happened over the course of his adventure. The wish is granted, and a wave of magic erased everything that happened including Vicky's firing, Tootie's evidence against Vicky and her, Chester, and A.J.'s memories of the event.
With everything peaceful and back to normal, Timmy decides to bury a time capsule, which includes a photograph of Timmy and his two goldfish. He buries it next to a flower and a tree, and tells Cosmo and Wanda that when he is grown, he will not make the same mistakes that his parents made. Wanda says that it is a beautiful day and there is so much to do outside, but Timmy and Cosmo would rather go inside and watch television.
20 years later, the future Dimmsdale is a normal, technologically advanced place. Timmy's children, Tommy and Tammy, are unearthing Timmy's old time capsule. The children take the time capsule to their father Timmy, who is now a working man at the age of 30, dressed in a tie and getting ready for work. His children ask about the time capsule, as Timmy views the photograph he removed from it. As a result of his age, Timmy no longer remembers his fairies and sees only normal goldfish. Timmy pockets the picture and leaves for work, ironically leaving his children under the care of a violent babysitter robot modeled after Vicky. His children beg for him to take them with him, when it's revealed that Cosmo and Wanda are watching over them as goldfish like they did for Timmy 20 years ago, they remark that some things never change.
- The Bowser Family will guest starring in this film and will be working for Vicky.
- The Justice Acre Wood Brood (excluding Timmy Turner, Cosmo and Wanda) will be absent in this film, due this is a past adventure.
- This film will be dedicated to the loving memory of Adam West (1927-2017), who made a cameo voices appearances and died form Leukemia.
- Delete song If I Lived in TV from real will be used for the end credits in this film.