The kids are going to learn about Thanksgiving in class; the school has brought in a real live 1/16th Native American as a guest speaker. The guest speaker, who is more white than anything else, talks about how history has portrayed the Pilgrims as heroes and have perhaps started the genocide of the entire Native American race. The guest speaker assigns the kids to write a report on Thanksgiving. Instead of reading books for their reports research, Cartman suggests they just watch the specials on Thanksgiving that the History Channel is probably showing back to back. On the History Channel they do find there is a program about Thanksgiving; however, the show has a decidedly alien influence to them. Despite his initial objection, Kyle agrees to go along with the plan and they write and turn in the report. Elsewhere, late at night, a man receives a phone call; he believes something has come up that is going to be just what he's been looking for. After school the boys get off the bus, when they are picked up by men in a black car. They are taken to the headquarters of the History Channel. The man who was awoken is the head of the History Channel and he wants to know what the boys know about the aliens. Kyle tells them they only know what they learned on the History Channel, but that very valid point just seems to be ignored. Stan makes a comment about stuffing and the head History Channel guy wants to know if he'll say that on camera. Back in South Park, Butters dad forces his to start watching the History Channel. Ancient Aliens at Thanksgiving Part 3 is the show currently airing and the show features interviews with Stan Marsh History Expert and Kyle Broflovski, Ph.D. : Professor of Thanksgiving - DeVry Institute. Kyle makes an offhanded comments about drawing a turkey using the fingers on your hand as a symbol and tries to argue against the Pilgrims and Indians all being aliens. Kyle, Stan and Kenny are all watching the program when the school's guest speaker comes to confront Kyle about the theories he has put forth. The guy pulls a gun on them. The History Channel is on their way to Plymouth Rock, the head guy is shown where Kyle's hand symbol theory has basis in fact. Plymouth Rock might just be the gateway to a wormhole. They try putting a symbol on the rock, but it doesn't work. They decide Pilgrims couldn't be from space. Meanwhile, from space, a man that looks like a Pilgrim has fallen and crash-landed on Earth. The History Channel guys realize that Professor Broflovski was right after all. In a galaxy far, far away on a planet called Plymouth, the Pilgrims have gathered for a meeting. They are concerned about their missing Captain and that their stuffing mines are being attacked by the Indians. On the Indian homeworld, the Indians are planning the attack that will get them all the Pilgrim's stuffing.
Cartman comes home to warn his mom about an impending stuffing shortage he's heard is coming. It's too late when the go to the store and find out all the stuffing is gone. The Indian ambassador meets with the Pilgrims. The Pilgrims threaten war, but the Indians know that with their Captain missing the Pilgrims won't stand a chance. The Pilgrim king wonders what has happened to Miles Standish. The guest speaker is still holding the boys hostage, when Miles Standish breaks into the room. He asks the "Indian" why his people sent him to the Earth. The "Indian" has no idea what he's talking about and is disintegrated when he fails Miles Standish's test to see if he was a real Indian. Miles Standish gets the boys to join him and Natalie on their trip to Cape Cod. The History Channel finds out more about their Pilgrim and are convinced they need Professor Broflovski's help. The Standish party camps for the night, and Miles helps Kyle to understand the truth about how things really were and are. The History Channel finds the party and agrees to take to Plymouth Rock.
On Plymouth, word comes that their attack on the Indian homeworld didn't go very well. The Indians have seized control of the stuffing mines. Miles Standish details out his plans to get back to his homeworld and regain control of the stuffing mines. He's tells the History Channel folks that they got the right symbol, but they were missing the keeper of the portal, Natalie Portman. They need her to open her wormhole, but she isn't budging. Kyle goes out to dinner with Natalie, hoping to get her to change her mind. They return to Plymouth Rock and she eventually decides that she'll open her wormhole, but "just for a sec." Miles Standish returns to Plymouth and regains control of the stuffing mines. Thanksgiving is saved, or is it? The History Channel's latest special, speculates that the first Thanksgiving may have been haunted.