Shrek interrupts the wedding to tell Princess Fiona how he feels and Fiona reveals her secret to Shrek. Lord Farquaad orders their arrest, but Donkey arrives on Dragon to save them. Dragon eats Farquaad and the town cheers, freed of the lord's oppressive reign. Fiona takes love's "true form" and discovers that beauty is more than skin deep. Back at the swamp, Shrek, Fiona, Donkey, Dragon, the fairytale creatures and the townsfolk live in harmony, happily ever after.
Shrek, Donkey and Princess Fiona's friendship grows as they travel to Duloc. Donkey interrupts a special moment between Shrek and Fiona, reminding them of the sun setting. Panicked, the princess escapes to a house to avoid Shrek seeing she is cursed. After convincing Shrek to tell Fiona his true feelings, Donkey goes to find the princess and discovers her secret. As Fiona tells Donkey of the curse, Shrek mishears their conversation and believes Fiona thinks he's ugly.
Duloc soldiers of set up a trade-in stall for fairytale creatures. As creatures with magical powers are imprisoned in cages, Donkey pretends not to speak. When an accident sprinkles him with fairy dust he flies away, taunting the soldiers. Unfortunately, the magic wears off and Donkey makes a run for it, bumping into Shrek. Shrek scares off the soldiers and Donkey decides to stick around. Shrek is not as enthusiastic about his new houseguest.
Shrek and Donkey defeat the soldiers Lord Farquaad set upon them. Farquaad crowns Shrek the winner and tells him he's "won" a mission. Shrek protests, explaining he was already on a quest to get his swamp back. Farquaad cuts a deal. Donkey and Shrek set out on their new quest to rescue Princess Fiona. Along the way, Shrek explains that ogres have layers and that there is more to ogres than people know.
Shrek storms the church to declare his love for Princess Fiona.
Donkey attempts to comfort Princess Fiona when she is at her most vulnerable.
Fairytale-hating Lord Farquaad tortures the Gingerbread Man to learn the location of the other creatures. When the Magic Mirror arrives, it tells Farquaad he will only be king if he marries a princess. The mirror shows him Today's Eligible Bachelorettes, a game that imitates contemporary reality TV. Farquaad chooses Princess Fiona but doesn't wait to hear she is cursed to transform into an ogress. Meanwhile, Shrek and Donkey have arrived, finding Duloc castle eerily quiet.
Shrek is pushed to his limits when his once-peaceful swamp is inundated with new residents after Duloc's ruthless ruler, Lord Farquaad, evicts them from his kingdom.
Princess Fiona is "rescued" by a legendary outlaw during their voyage from the castle to Duloc.
Junior scientist Cassidy shows us how to make growing grass heads at home and explains why plants grow better with access to sunlight. To germinate these grassy pals, you'll need a pair of old stockings, some grass seeds, cotton wool balls, small yoghurt containers, a spray bottle, string, glue, googly eyes and some pipe cleaners.
Sally and Conrad's mother, Joan, is called back to the office before a big party. Joan calls sleepy Mrs Kwan to babysit and forbids Conrad and Sally from entering the living room. Shortly after arriving, Mrs Kwan turns on the TV and falls asleep, leaving the kids glum and staring out the window. When a large thump startles them, they go to inspect, finding a large, mischievous, anthropomorphic cat that wants to balance out their fun levels.
Sally and Conrad return a purple tornado to a crate, hoping it would restore the damaged house, but the building falls apart. The children are upset when Cat takes credit for containing the twister. Conrad tells Cat there has to be limits to their fun. The two kids tell Cat it's time to get out of their house. Looking around, Conrad decides to take the blame for the damage, but Sally stands by his side telling him to share the burden. Learning their lesson, Cat returns to fix the house.
Conrad taunts that Sally would never break a rule, and the fish asks her not to, but ultimately he decides to join Cat on the couch. Lawrence walks in to find the living room in shambles, and Sally tries to pretend it was all Conrad's fault. Lawrence tells her that no-one likes a suck up. Sally and Conrad bond while laughing at horrible Larry and his allergies.
Joan arrives home to find the house in pristine condition and everything in order. Lawrence enters, covered in a purple slime, and tells Joan all about her "terrible" children. Joan, thinking he's crazy, sticks by her family and asks him to leave. At the party, Hank Humberfloob congratulates Joan on her perfect event and immaculate home. Later, the family is seen jumping on the couch together as Cat narrates the final scene.
Joan's boss, neat freak Hank Humberfloob, has organised an office party, threatening messy guests with termination. Joan's daughter, Sally, is clean, well-behaved and overly mature. Her son, imaginative Conrad, has earned a reputation as a "troublemaker". After work, Joan finds that Conrad has developed a new sport, "stair luging". While cleaning Conrad up, Joan's squeaky clean and ill-intentioned partner, Lawrence 'Larry' Quinn, reveals his plan to send Conrad to military school.
Conrad, Sally and Cat intercept Lawrence before he can deliver the dog and incriminate Conrad. A chase ensues and, although Sally, Conrad and Cat, successfully retrieved the dog and the lock, Lawrence collects Joan from work attempting to convince her of the children's mischief. Downtrodden, the three think their chances are dashed, until Conrad realises all he needs is reverse psychology to get the Things to help them beat scheming Larry.
Thing 1 and Thing 2 run riot in the Walden home, Conrad breaks an old rule and unlocks a crate, and Cat warns of the terrible consequences to come. Lawrence 'Larry' Quinn turns out to be a toothless, rotund, slob with credit card debts. When Larry notices the little dog has run off again, he calls Joan and reminds her of military school.
Diego suggests a shortcut. Locked in a cave, they pass fossils from the Palaeocene, Miocene and some of the earliest organisms, even some objects from science fiction. When Roshan slips down a tunnel, they are forced to follow. The scene resembles contemporary human activities, such as luging and theme parks. After they recover the child, Manny, Sid and Diego discover a cave full of paintings and learn a little more about how Manny lost his family to human hunters.