In school, Stan questions what Mr. Garrison is teaching. He asks why they can't be like normal kids and do stuff like field trips. Garrison answers that they are actually going on a field trip to the planetarium tomorrow. At the planetarium, the kids watch a laser show involving stars, except for Cartman who spots the Cheesy Poofs van that is auditioning kids for the Cheesy Poofs advert. Cartman is successful and makes it to the next round.
In the planetarium, the laser show takes an unusual twist and begins to hypnotize everyone. The kids all say they want to visit the planetarium again right after leaving it; they have been successfully hypnotized to actually like the planetarium. The next day, Cartman goes to his audition and makes it through to the finale and discovers he will be appearing on television. Later, the kids go back to the planetarium to be hypnotized by the spinning stars again and they're hypnotized so much that they all become volunteers there.
On the school bus, Van Gelder, a crazed kid from the planetarium shows up. He has escaped from there and is sent to Nurse Gollum upon arrival at school. In the nurse's office, Mr. Mackey tries a mind to mind technique (mind-meld) which helps Mr. Mackey discover what's going on. Stan, Kyle and Kenny realize something isn't right - kids don't volunteer for things. Stan and Kyle work the laser machine and see how it affects Kenny. They begin by turning the dial to a lower setting, which doesn't affect Kenny at all. So they turn the dial up higher and the stars begin to move; Kenny is hypnotized by the other boys into a helpless hypnotic trance and can't answer. They decide to turn the hypnotization dial to the highest point and it kills Kenny by blowing up his head. His mind couldn't take the powerful hypnosis and his head exploded.
Stan and Kyle go to Officer Barbrady and ask him to arrest the owner of the planetarium, Dr. Tristan Adams. Barbrady is hypnotized by the laser machine and convinced he is Elvis Presley. Cartman appears on TV but discovers that none of his friends watched it because they were at the planetarium—he doesn't realize that they are in a hypnotic trance. Mr. Mackey shows up at the planetarium, himself and the boys are soon taken to be hypnotized. As they watch the lasers and are entranced into a hypnotic slumber, Cartman bursts in. An angry Cartman smashes the laser device. It swings around and beams bright white light straight into Dr. Adams' eyes. By the time Cartman unties everyone and turns off the machine, Adams' mind has been completely erased. Stan and Kyle muse about the power of the machine that Dr. Adams built, but Cartman is just happy to be the hero for once.