Lynn and her roller derby teammates, Margo, Maddie and Paula, arrive at the Burpin' Burger to celebrate their latest victory. As they eat, Paula reveals that because they won their latest match, they won tickets for a free entry into Dairyland. Margo expresses excitement to ride the park's roller coaster, Whipped Scream, where everyone who rides it is vulnerable of throwing up. As they discuss, Lynn is shown to be stricken by fear, but Lynn denies that she's scared of anything.
At the middle school, Lynn approaches Clyde for help. Lynn tells Clyde that she and her friends are going to Dairyland, and that they want to go on Whipped Scream. However, Lynn is afraid of going on the roller coaster, as she has an intense fear of throwing up, having gotten it after one incident of her throwing up when she was younger, and it resulted in the taste of her vomit being stuck for a week. When Lynn asks how she can get over her fear of throwing up, Clyde tells her that she has to live with it, and to be honest with her friends by saying that she's not comfortable with riding the coaster.
The next day, Lynn and her friends arrive to Dairyland. Margo and Maddie state that they want to go on Whipped Scream, but Paula admits that she doesn't want to ride it, saying she's not comfortable. Lynn attempts to confess as well, but before they can, Margo and Maddie give her a hard time by saying that while they go on Whipped Scream, she can go the baby rides. Paula takes back what she says, and Lynn, fearing that she'll be ridiculed if she confesses, decides to stall the two by saying that they should explore the rest of the park, to which they agree with. First, they decide to watch the process of churning butter, which takes around 60 to 90 minutes (the same amount of time it takes to properly churn butter). Second, they ride on Seas of Cheese, a tunnel of love style ride with animatronics. Suddenly, the ride shuts down, and Lynn decides to use that to stall even further. 60 minutes later, Margo says she's starving, and Lynn attempts to convince her to eat the ride's cheese curds and milk that keep the boats afloat. Disgusted and tired of waiting, Maddie and Margo decide to swim out of the ride, with Lynn and Paula following behind. Third, Lynn decides to visit the petting zoo, which is housing Ursula, "the angriest cow in Michigan". By now, Margo and Maddie have become suspicious of Lynn's stalling, and decide to not fall for any more of her tricks.
As the girls wait in line at Whipped Scream, Lynn chugs a large cup of a cheese-flavored cappuccino. When Maddie sees that they're next, Lynn tosses her drink onto the ride's control panel in the hopes of shutting it off. While she succeeds at first, it suddenly reactivates and now goes twice as fast. Suddenly, Lynn hears Ursula bellow loudly. Excusing herself, Lynn decides to let Ursula loose from her corral, causing Tippy to tell the attendants that a mad cow is on the loose. As everyone flees the park for their safety, Margo and Maddie express dismay that they haven't gone on Whipped Scream yet, but Lynn claims that they can go another time. Suddenly, Tippy arrives and reveals to the girls that today was the final day Whipped Scream will be in operation, as it will be torn down to make way for a Dairyland hotel. Feeling bad for costing her friends their chance to ride a roller coaster on its final day of operation, Lynn excuses herself.
Entering Dairyland, Lynn attempts to fight Ursula in an attempt to get her back in her corral. After a brief struggle, Lynn succeeds in getting Ursula back into her corral by treating her like a roller derby opponent. With Ursula contained, Lynn declares that the park can reopen. Catching up with her friends, Lynn ultimately admits that she didn't want to ride on Whipped Scream because of her fear of throwing up, and says that she didn't want to be ridiculed if she confessed. However, Margo and Maddie actually go easy on her, and say that if she's not comfortable, they won't force her to ride the coaster (Paula also reminds them that they were hard on her when she confessed, prompting them to apologize to her).
As Lynn and Paula sit on a bench while Margo and Maddie ride Whipped Scream, Lynn suddenly feels nauseous. Lynn realizes that during her attempts to stall her friends, she would do things that would evoke her stomach, like eating the cheese curds and milk from Seas of Cheese, drinking the cheese-flavored cappuccino, and riding on Ursula. This causes Lynn to feel even more queasy and nauseous, and this makes her vomit into a nearby trash can. Lynn realizes that the experience wasn't as painful as last time, and discovers that she has gotten over her fear. At that moment, Margo and Maddie arrive, and Lynn tells them that she has gotten over her fear of vomiting, and decides to join them on riding Whipped Scream. As for Paula, she decides to stay behind to hang out with a boy who has an injured leg in a cast.