Monsters Inc. 2: Lost in Scaradise was a canceled sequel to Monsters Inc. It would have been produced by Circle 7 Animation, a company owned by Disney. It was gonna revolve around Mike and Sulley going to the human world to see Boo in time for her birthday. However, they instead find an old woman in her room. Trapped in the human world, Mike and Sulley must embark on a quest to find her and return to their world.
Pixar had a contract with Disney that would let them make 7 films on their own, with Disney only involved for distributing purposes. After this contract ended, rights to all franchises originally produced by Pixar would belong to Disney including rights to making sequels. When the 7th Pixar film, Cars, was finished, Disney formed another animation company known as Circle 7 Animation who began working on drafts for Toy Story, Monsters Inc., and Finding Nemo sequels. All of these planned sequels were cancelled, but most movies that were planned to get sequels via Circle 7 eventually did through Pixar.
In early 2006, it was decided that Disney would be better off owning Pixar altogether rather than just the franchises. As a result, Circle 7 Animation was shut down thus cancelling the drafts of the Toy Story, Monsters Inc, and Finding Nemo sequels, although Toy Story and Finding Nemo eventually got sequels made by Pixar, and Monsters Inc got a prequel.
One year after the events of the first film, on Boo's birthday, Sulley and Mike go to her house to wish her a happy birthday, however, when they get there, they find an old lady asleep in her bed. This leaves Sully and Mike to think that Boo has moved to a new home, so Mike and Sulley set out to find her. The full summary goes as follows:
The story begins at the wedding of Mike and Celia. Right before Mike could say "I do", he faints. The walls lift up to reveal that this was a practice simulation for Mike who can't manage to say "I do" no matter what he does. It makes Celia delay their wedding three times already and she's furious. She tells him that if he's not ready to say I do at their wedding that Sunday, she will never marry him.
Later that day, Sulley who is now the CEO of Monsters Inc is visited by Roz and they get to talk if he ever misses the old days of being a top scarer. Sulley doesn't miss scaring kids, but he does miss spending time with Mike and how they're going to spend even less time together once Mike is getting married and moving out. It's clear that Sulley is happy for everybody else's successes and bright futures, but he doesn't exactly feel comfortable and happy where he is. This is made more evident when he loses his temper at work.
After making a mess and cleaning it up due to losing his temper, he comes across Boo's file and instantly becomes lost in a flood of memories of his past few years visiting Boo, such as teaching her a monster's lullaby, Boo showing him a loose floorboard in her room where she keeps all of her valuable and her drawing with a glow-in-the-dark pen. Mike enters the room, breaking Sulley's days. He tells Mike that it's Boo's birthday tomorrow and invites him to come visit her. But Mike says he can't, because he's going out to a pre-wedding lunch with his and Celia's family.
As they exit the factory, Mike is confronted by the wealthy and self-obsessed Reginald Flankbottom, Celia's ex-boyfriend who belittles and berates Mike for not being able to say "I do". After picking up Mike's family from the airport, he and Sulley spend the night packing up his stuff from the apartment. They reminisce and laugh as they pack up old pictures and talk about how not that much is going to change with Mike moving out, but deep down, they both know that things will really never be the same as before. After an awkward beat of silence, Mike tells Sulley that he can afford to be late to lunch tomorrow and that he'll come with him to see Boo.
The next morning, Mike and Sulley try to open Boo's door, but for some reason, her key card isn't working. Sulley tries to open the door with all his strength and he ended up forcing it open. They approach the bedroom, but there's one problem: Boo is not there. Instead, they find an old woman sleeping in her bed. Mike and Sulley can immediately tell that something is very wrong. The old woman wakes up. Mike panics asks Sulley if she can see them, but Sulley responds by telling Mike that she is way too old to believe in monsters, so they are essentially invisible to her. Sulley checks underneath the loss floorboard and sure enough, Boo left him a letter. It reads: Dear Kitty, I have moved to a new house.
Just then, the old woman's dog tries to attack Mike causing him to backpedal into the closet door, accidentally closing it. And since this isn't technically a kid's door anymore, they can't use that door to get back. They are stuck in the human world. They leave the house and try to find a new one with kids inside of it, which they eventually do. It isn't just one kid there, but an entire slumber party. Despite this, they end up promptly botched their escape attempt, getting scared by the younger brother sleeping upstairs and bolting from the house into the back of a newspaper delivery truck. The kids inside the house are freaking out, begging the parents to call the police, because there's something in the house. As the police wrap up, reporting the call to be a false alarm and realizing that the kids are talking about a monster in the house.
This caught the attention of Simon Nerlich, a nerdy 30-something and a self-proclaimed monster hunter, who was listening in on his police scanner. He decides to visit the kids of that house where he gets a description and drawing of what the monsters looked like from the kids.
Meanwhile in Monsters Inc., Celia, her family and Mike's family wonder why he's running late to their pre-wedding lunch.
Back at the Human World, the newspaper truck comes to a halt and opens its door. Mike and Sulley find themselves in a sprawling city. Hijinks and sue would see Mike fall down a manhole and as Sulley pulls him up from the sewer, his horn is ripped clean off the left side of his head. Mike's misfortunes continue as he gets attacked by toddlers and gets hit by a car. At this point, Mike is furious. Blaming Sulley for his missing horn, he grabs Sulley's horn and starts gnawing on them in retaliation, which catches the attention and laughter of a little girl. Mike and Sulley follow her back to her house and try to use her door to return to the monster world, but it doesn't work. They try another kid and another, but for some reason, none of the closet doors are working.
Completely demoralized, they walk along a city street until they come across a comic book shop. In the front window, they notice a display advertising a new comic book and are surprised that the monster in display looks just like Randall. They slip into the store and find the comic which claims that the monster lives in the swamps of South Florida, which Sulley noticed that it isn't too far away. Sulley speculates that Randall may actually be able to help them figure out how to go back to the monster world. Mike obviously rejects, but Sulley points out that he is getting married tomorrow, they have no choice. As they leave the store, Simon, who works at the shop, manages to get a glimpse of the two monsters. After failing to chase them down, he notices the swamp creature comic book on the ground and knows exactly where they are going.
Simon and his co-worker Rodney go to the swamps in his van. Rodney is excited to see a real monster, but Simon explains to him that seeing monsters is an ability that very few adults have. Mike and Suley steal and crash an airboat, but eventually make it to the swamps and find Randall. Sulley asks for his help, but he refuses. That is until Mike and Sulley managed to rescue him from being captured by Simon. They promise him to unbanish him if he helps them get home. Randall explains that every year around this time, all of the banished monsters meet on an island in the Bermuda Triangle to socialize and that he knows a monster there that might be able to help them.
Sulley asks how to get to the island and Randall explains that just like how the laughs and screams of kids create energy in the monster world, monsters emit a ton of electromagnetic energy in the human world and that this energy allows monsters to ride inter-dimensional air trails in the sky to a vortex in the Bermuda Triangle. The three of them steal a ton of balloons and float into the sky. And once they get high enough, they are sucked into the jet stream of stratospheric energy and are hurled through clouds, rain and electromagnetic flares of light, before eventually bursting out of the clouds and finding themselves floating above a beautiful tropical island.
Back at the restaurant, everybody including Mike's family begin to doubt that he'll make it to lunch. Just then, Flankbottom, who's been hiding out in the corner of the restaurant, lying in wait to win back Celia's heart and marry her tomorrow instead of Mike, makes his way over to the table and tells them that Mike sent him to tell them that he and Sulley got caught up in a work emergency and that he's sorry he missed lunch, but he will definitely be at the wedding tomorrow. Instinctively, Celia throws her arms around Flankbottom and everybody from both families remark just how great she is.
Mike, Sulley and Randall make their way to the beach and are greeted by none other than the Abominable Snowman. Randall asks him if he knows where El Chupacabra is. The Abominable Snowman leads them to an entire monster island resort before they eventually wind up at the official mixer for the banished monster association, passing by monsters such as the Jersey Devil, the Loch Ness Monster and the Mongolian Deathworm in the process. At the party, a sexy voice calls out to Sulley. He turns around to see his ex-girlfriend Anastasia, a female sasquatch. Sulley thought she left town after a fight they had. But it's revealed that Waternoose actually banished her. It that didn't happen, Sulley and Anastasia would have likely still been together. There's still a romantic spark between the two. But before anything could happen, Randall grabs Sulley and tells him that he found El Chupacabra.
As Mike, Sulley and Randall enter El Chupacabra's office, there's a tense atmosphere. Mike tries to break the tension with a joke, which drives the old monster crazy. He rages on how he designed the original doors and how when he questioned their unethical use, Waternoose banished him how after 40 years being stuck here, Mike comes to him with jokes. Sulley tells him that Waternoose is gone now and he is in charge and that in exchange for his help, he will pardon all of the banished monsters when they get home. El Chupacabra is overjoyed and explains that to get home, they need to find Boo and go through her door to return to the monster world. Mike and Sulley realize that they still don't know where Boo's new house is and Mike storms out, resigned to the fact that he's never getting married, and that they are stuck to the human world forever.
Sulley makes his way to the beach. He sits alone and reads Boo's letter again. Defeated, he looks out over the horizon as the sun sets. But as it does, the letter begins to glow, he looks back down at the letter and the second half written in glow-in-the-dark ink reveals itself, showing Boo's new address. Back on the mainland, one of Simon's gadgets goes off, detecting a massive influx of electromagnetic energy 20 minutes away.
Mike, Sulley and Randall makes their way to Boo's new house, showing up in the middle of her seventh birthday party. Despite Sulley wanting to reunite with Boo more than anything, he knows what needs to be done. The three of them sneak into the house undetected, find her room and open her closet door. Only to see the inside of an ordinary closet. Boo rushes to her room and Sulley is overjoyed, he calls out her name, but she doesn't acknowledge him. Sulley tries once again to get her attention, but nothing happens. The reality of the situation is that Boo can't see Sulley, she doesn't believe in monsters anymore. Sulley is devastated
Randall blames Mike for the situation and at this point, Mike is going to miss his wedding. He's had enough, the argument quickly shifts to one between Mike and Sulley. He lunges at Sulley, but is held back by Sulley's huge wingspan. The tension is broken by a laugh. They turn around and see Boo's little brother, who approaches them with a drawing of he and Mike. He knows exactly who Mike Wazowski and Kitty are. Randall tells them that it doesn't matter if he knows them, as long as Boo doesn't, they are stuck. They realize they need to remind Boo of their existence if they want to go home.
After a failed attempt at teaching Boo's brother stand-up comedy, Sulley notices Boo singing outside and has an epiphany. He takes Boo's brother to the far corner of the yard where they are having her birthday party and they start to sing the monster's lullaby that he used to sing to Boo. Boo hears from her brother and breaks off from her friends. As she approaches to him, the song starts to have a hypnotic effect. She harmonizes with her brother and begins to see Sulley materialize in front of her and is overcome with emotion. Boo and Sulley hug. Just then, Simon bursts into the backyard and tackles Sulley to the ground, but quickly realizes that he didn't tackle Sulley, a man in a dinosaur costume who was entertaining other kids at the party who all promptly begin to beat him up.
Sulley and Boo slip away into her room, she gives Mike a hug and gives Randall a slap. They notice the commotion outside and Mike and Randall head toward the door, urging Sulley to hurry up, which leaves Boo both sad and confused asking if he's leaving already. Sulley hesitates for a second before leaving Boo with a really unsatisfying goodbye. As Boo leaves her bedroom, Rodney pops out from under the bed and catches the closet door right before it closes, leaving it open just a crack. Simon enters the room and Rodney explains to him how they just left using the closet door. Simon immediately decides to follow the monsters into the monster world so he can capture a monster for himself and prove their existence.
The lobby of Monsters Inc has been transformed into a beautiful wedding chapel. All the guests are gathered, but they are also annoyed since Mike is 45 minutes late to his own wedding. Flankbottom tries to make a move on Celia when Mike bursts in and explains to Celia what's been going on. Sulley calls down a series of doors to the laugh floor and one by one, all of the banished monsters emerge, except for the Abominable Snowman, who they all forgot to tell that this was happening. As they exit to go to the wedding, Simon pops out from behind one of the doors and begins to snoop around the factory.
While Sulley and the new pardoned monsters hustle to the ceremony, Mike is already standing at the altar finally ready to say "I do". And just as he's about to, Simon shows up and sends everyone into a blind panic. Simon kidnaps Celia in the commotion. Mike and Sulley take off to save her. As they search for them, they manage to find Simon's wallet and driver's license on the floor. They find Simon in the laugh canister storage room. He stands on one of the shelves throwing the canisters down at Mike and Sulley and on impact, the seals of the bottom of the cans crack, releasing highly pressurized laugh energy, shooting off like missiles and flickering all of the lights. In the chaos, Simon and Celia escape, while Mike and Sulley are covered with an avalanche of canisters.
Roz, Randall and the pardoned monsters burst into the room to help dig them out. When one of the stray cans pops off and scores a direct hit on a wall full of canisters, the set of cans begin to teeter, and if it falls, the outcomes would be catastrophic. So the pardoned monsters work together to steady the wall as Mike and Sulley continue their chase. Simon bumps into Flankbottom and demands to know where the doors are. Celia pleads for help, but he cowards and tells Simon immediately. He and Celia make their way to the door vault using a maintenance platform. Simon jumps up and grabs one of the doors. He and Celia are going for a ride.
Mike and Sulley chase them up to the maintenance platform and quickly realize that they are too far away. But seeing a cart of full left canisters, Mike gets an idea. He mounts one of the cans and demands Sulley to break canned seal. Nervously, he does so. Mike rockets towards the doors and grabs Celia before the can runs out of energy, sending the nearly weds plummeting hundreds of feet as Simon escapes. But right before they hit the ground, Sulley riding two canisters swoops in and saves them before landing.
Sulley pulls a kill switch to stop all the doors and rushes to his office ripping through a bunch of papers. Eventually, everyone convenes on the laugh floor. As they enter, Simon is able to guess his way into activating a door. The others tell Sulley to just let him leave, but Sulley knows better, if he lets Simon go, he still knows how to come back and others will come too. Sulley plants himself between the door and Simon who meets Sulley face to face and threatens him. Sulley flips the conversation when he pulls out Simon's old file from when he was a kid whom they used to scare at the factory. One of his particular fears happens to be hairy monsters with fangs. Sulley unleashes a truly terrifying roar at Simon as he screams out in fear. The pardoned monsters also descend on him and Sulley knows what exactly the place in the human world he's sending him back to.
At the wedding ceremony, the newlywed celebrates, Flankbottom walks away in defeat and Roz flirts with The Loch Ness Monster and El Chupacabra. As the music dies down, Sulley turns to Mike and tells him that he's quitting management, he toasts to new beginning and Mike, unsure of the future, reluctantly clinks glasses with his best pal. Meanwhile at Boo's room, she and her brother are laughing out loud at the comedic show of Monsters Inc's newest comedic duo: Mike and Sulley. As they finish their routine, Sulley tucks Boo into bed and tells her that he will always be there for her. Boo hugs Sulley and tells her newly remembered friend that she will never forget him. As they exit the room, Mike reminds him that eventually Boo is going to forget him. Sulley turns to Mike and tells him: Yeah, I know, but that's okay, I'll remember for the both of us.
- In early 2006, it was decided that Disney would be better off owning Pixar altogether rather than just the franchises. As a result, Circle 7 Animation was shut down thus canceling the film and letting Pixar make a prequel (Monsters University).
- The film was canceled, and will likely never be released.
- A comic series known as Monsters Inc. Laugh Factory served as a continuation of the 2001 film.
- A prequel to Monsters Inc. titled Monsters University was released in 2013.
- A world based on Monsters Inc appeared in Kingdom Hearts 3. The story on that world is implied to be after the events of 2001 film, though this could be non-canon.
- A direct mid-quel Disney+ show called Monsters at Work which was planned to be released in 2020 but later delayed and was later released in 2021 instead (20 years after Monsters, Inc.).