Chrissy Goldberg, Asta Paredes, finds herself tangled in a new round of trouble when Principal Westly, played by Babette Bombshell, uses a secretly recorded clip of Chrissy kissing Catherine Corcoran as Lauren to pressure her into deleting her blog. In the midst of this blackmail, Lauren reveals a wild and unsettling secret: she has given birth to a duck/human hybrid in the gym locker room, explaining to Chrissy that she was impregnated when her pet duck Kevin was forcibly inserted. In a bid for revenge against the betrayer, Chrissy and Lauren steal Zac Amico's clothes, triggering Zac to declare war on them after he is admitted into the Cretins. The tension between them sets the stage for a chaotic confrontation that blends teen drama with science‑fiction horror.
The next morning brings a stunning family revelation. Aunt Bee and science teacher Mr. Chip inform Chrissy that she is the daughter of Chrissy and Warren from the first Class of Nuke 'Em High. Warren grows up to become Lee Harvey Herzkauf, who is secretly plotting with the President of the United States to flood schools with toxic tacos. He also uses the flatulence gas of Tromaville High Students to stay young. Meanwhile, Kevin is dumped into a toxic waste vat and mutates into a hulking duck monster, turning the town’s oddities into a full‑blown crisis.
When reporters arrive to probe Chrissy about her blog, Lauren comes out publicly as part of a lesbian couple to stand with Chrissy in the fight ahead. The Cretins break into Chrissy’s house, kidnapping Lauren and the baby, and drive them to the school where a deadly siege begins. Herzkauf begins mutating as he exhausts his energy and resources, turning into a monstrous figure that hunts through the hallways and massacres scores of students. Chrissy, Slater, and Kelly venture into the school to find Lauren, only to be captured and taunted by Zac and the other Cretins, who threaten violence and sexual assault. Kevin bursts in and murders Zac, scattering the attackers and sending the chase after the baby into the building’s corridors.
As chaos erupts, Slater sacrifices himself by leaping onto a grenade and dying in the room, while Chrissy makes contact with the nearly fully mutated Herzkauf. Kelly is killed as Herzkauf’s rampage continues, escalating the stakes for everyone involved. Lauren seizes Mr. Chip’s laser, fires a shot into the sky that destroys God, and then shares a courageous kiss with Chrissy to unleash a combined blast that finally defeats Herzkauf. The school erupts in flames as the dust settles, and Chrissy addresses the surviving students in a speech about ending hate and homophobia, signaling a new era for Tromaville.
In the wreckage, Kevin emerges with the baby and returns the child to Lauren, choosing to sacrifice himself and Principal Westley in a final act of defiance as Westley tries to escape. The town begins to heal, and in a quiet, hopeful moment, Lauren and Chrissy marry in a private ceremony beneath a rainbow, promising a future built on acceptance, resilience, and a love that has endured through the strangest of trials.
