Schmidt and Jenko are ordered to go undercover as high school students and attend the local high school to gather information about the supplier. However, their roles are reversed as Schmidt becomes the popular jock, while Jenko is branded as an outcast. The two struggle to fit in with their new identities, but eventually, they overcome the challenges and infiltrate the drug ring.
The drug ring is led by a popular student named Eric, who uses his status and influence to supply drugs to the entire school. Schmidt and Jenko also discover that their old high school rivalry has carried over to their undercover mission as they compete to impress a girl named Molly, who turns out to be the supplier's girlfriend.
As they get deeper into the case, Schmidt and Jenko realize that the drug they are dealing with is much more dangerous than they thought, and they need to take serious action to stop it. The moments of comedy come in with their attempts to fit in at high school, and the two characters' opposing personalities make an interesting blend of humor and action.
In the end, Schmidt and Jenko successfully bring down the drug ring, but not before getting into a wild car chase and finding themselves in hilarious situations. As the mission comes to an end, the pair graduates from high school (again) and replan to join the police force.