The kids are presenting their reports in front of the class and Cartman's topic is "Ginger Kids - Children with Red Hair, Light Skin and Freckles." He says that these kids suffer from "Gingervitus," which occurs because Ginger Kids have no souls and cannot be cured. Like vampires the Ginger Kids need to avoid the sun and don't go out during the day. Kyle interrupts and says that he has red hair and he goes outside. Cartman counters by classifying those with red hair, but no light skin and freckles as "DAYWALKERS," using a picture of Kyle as an example. Cartman tells Mrs. Garrison that he can't proceed with his paper with all the interruptions. Mrs. Garrison tells Kyle that if he wants to debate with Cartman, he will have an opportunity tomorrow when he gives his presentation. Kyle is angry when he comes out of the classroom and he needs to disprove Cartman's hat mongering. Kyle and Stan go to the home of the Foley, where all the kids are Ginger. The Foley kid's parents give them some background on the Ginger gene, but when Kyle asks them if it is true that the "Ginger Kids" don't have souls, their father doesn't seem so sure. As parting advice the father advises them to marry an Asian woman. Kyle gives his report, which bores Cartman and Mrs. Garrison. Cartman warns everyone that the "Ginger Kids" will get you, after all Judas was a Ginger. It begins to work, as the Ginger Kids get banned from the cafeteria. Stan says he'd like Cartman to see what it is like to be a Ginger and Kyle thinks it's a great idea. Kyle, Stan and Kenny meet at Cartman's house, sneak into his room and proceed to make him into a Ginger Kid. The next morning Cartman wakes and finds to his horror that he is now a Ginger Kid. A visit to the doctor leads to speculation that Cartman might have had a recessive Ginger gene that was activated once he hit adolescence. The doctor recommends that Cartman's mother "consider putting him down." At the bus stop the next day, Cartman arrives at the bus stop and explains his new condition to guys and he misses the irony of his situation. On the bus, Butters cracks up at Cartman's appearance and Stan and Kyle believe their plan to teach Cartman a lesson might actually be working.
Cartman tries to eat in the cafeteria like nothing is wrong, but he finds that the hate he spread the previous week is now working against him. Kyle thinks that their plan has worked and Cartman is now going to think about he treated the Gingers. Quite the reverse begins to happen; Cartman has begun to rally fellow Ginger Kids into taking back their pride. On the playground Cartman and the Ginger Kids begin to shout "Red Power" and "Better red than dead!" In Denver, the "Ginger Separatist Movement," led by Eric Cartman, is protesting outside a theatre showing a new production of "Annie!" Their main contention is that Annie isn't be portrayed by a real Ginger. Later, at the Airport Hilton, the "All Ginger Pride Conference" is underway and Cartman is calling for the extermination of all non-Ginger kids. They are going to round up all the kids and keep them in cages until they thrown them into a pit of hot lava. That night Kyle, Kenny and Stan go to Cartman's home to turn him back into his former self, but on their way they encounter a group of Ginger Kids, who seem bent on exterminating them. The boys begin to run. Kenny is grabbed and Stan and Kyle run for their lives. The Ginger Kids have begun their elimination process and kidnap kids from all around town. Stan and Kyle try to take refuge in an old barn, but soon the Ginger Kids have them surrounded and caught.
The boys wake to find they are being kept in cages suspended from the ceiling of the Airport Hilton. In front of Cartman's stage there is a pool of hot lava. Cartman makes his opening remarks and decides that the extermination will start with the "DAYWALKER." Before Kyle is thrown into the lava as a last request he asks to say some private words to Cartman. Cartman grants him the opportunity to speak and Kyle tells him what they did to him. Suddenly Cartman sees the light and tries to backpedal his way out of their plan and learn to live together. "We've got to live and let live." The master manipulator that he is, Cartman breaks into a song that catches on with the crowd and all the non-Ginger kids are let out their cages and everyone is getting along.