Cartman needs to find out who his father is but his mom is no help. Learning that his father could be one of the many people that his mom "had relations" with during an annual party called "The Drunken Barn Dance" he finds that there's more to his mother then he thought.
The boys meet up with Barbara Streisand who wants to take over the world with Kyle's discovery and an archaeological dig. Leonard Maltin, Sydney Potier, and Robert Smith come to the rescue to defeat Bab's and her terrible destruction.
Wendy and Stan discuss their plans for romance. Principal Victoria comes into the classroom and announces that Mr. Garrison is going to be out and that a substitute will be taking his place. The lovely Miss Ellen speaks to Stan and he pukes all over his desk. Wendy is upset because Stan only pukes when he is in love and has Mrs. Ellen arrested for being a spy.
South Park Elementary is on stage rehearsing for the schools play. Kyle begins to sing a song about Mr. Hankey, the Christmas Poo. Of course, no one has any idea what the heck he's singing about. Kyle explains that Mr. Hankey comes every year to all the good boys and girls who have a lot of fiber in their diet. Everyone thinks he's insane and sends him to a mental institute.
The four boys are at Cartman's house watching the Terrance Philip Thanksgiving Special" on television. During a break from the show, a Sally Struthers commercial convinces the boys that the prospect of a free Taiko" sport watch with a five-dollar donation is irresistible. Typical greedy American youth. So Stan dials in, using his mother's credit card number and makes their donation. 
Eric is handing out invitations to his birthday party at school. Mr. Garrison informs them all that there is a new student joining the class. Announcing to all that he is Damien, the son of Satan. Even as Damien demonstrates his demonic powers the children are more loathsome than impressed.
The first Halloween episode starts off with the failure of the Mir Space Station, which crashes right on Kenny. An ambulance comes and takes his body off to the morgue. The boys start to brag about their Halloween costumes. At the morgue, a freak accident involving a bottle of Worcestershire occurs, and next thing you know Kenny is a member of the undead. Kenny breaks free and wanders off into the night.
Happy Birthday to Stan's Grandpa Marsh who just turned 102. How does the wizened Mr. Marsh feel about his birthday? He sums it up in five words; "I wish I were dead." and proceeds trying to end his life enlisting Stan to do it for him. However, Stan is aware of a very important thing if he kills his grandfather, he'd be in trouble, and if he's in trouble he can't watch Terrance and Phillip.
Stan notices a new addition in their bus stop crew, an elephant standing alongside Kyle. At school, class lessons for the day involve genetic engineering (conveniently enough). Kyle questions the possibility of a genetically engineered elephant made smaller by design. The boys have to beat the rough kids in their genetics experiment, and will try anything to do it.
Stan's got a new dog-named Sparky. Stan proclaims his pet to be the toughest on the mountain. Though while Stan thinks his dog is ready for fighting Sparky proceeds to hump Sylvester like a little bitch. The other boys taunt Stan about his gay dog and Sparky runs away to find someone who will love him for who he is.
Mr. Garrison starts the day off witdh a spacial announcement; one of South Park's own has won a national essay contest. Everyone is shocked to learn that the winner is Cartman, who doesn't even remember what he wrote about.
While the boys are waiting for the school bus, Cartman explains the odd nightmare he had the previous night involving alien visitors abducting him from his bed. Meanwhile Kyle and Stan to convince that the dream was in fact a reality.
