The gang begin their fourth year of college in the Season 4 premiere. Jeff focuses on the last few credits he needs to graduate; Dean Pelton arranges a physical challenge to award spots in a history class; and Britta helps Abed cope with his anxiety about the group parting ways after graduation.
The gang go to InspecTiCon, the annual "Inspector Spacetime" convention, where Abed meets his enthusiastic pen pal, causing a rift between him and Troy. Elsewhere, Annie ditches the convention to relax in the hotel, while Jeff meets an "Inspector Spacetime" fan at a bar.
The gang begin a European history course after missing out on an ice-cream class. Adding to their misery is an encounter with the arrogant German students they battled last year. Elsewhere, Chang returns to Greendale, much to Dean Pelton's chagrin.
The group try to secure a grant for medical research to get to the bottom of Chang's amnesia. Abed uses the opportunity to film a documentary, while Jeff becomes suspicious that Chang's memory loss isn't quite what it seems.
Dean Pelton tries to lure a wealthy student to Greendale and uses Jeff, Britta and Annie in his recruitment efforts, upsetting Pierce. Elsewhere, Abed starts a fraternity; Shirley shines in a phys-ed class while Troy struggles.
Annie and Shirley join forces against Leonard, who is ahead of them in the race for valedictorian. Elsewhere, Troy and Abed reenact a body-switching scene from a movie, and strange things start happening.