It's Greek week at Mali-U and Clover is psyched because she's going to pledge a new sorority, Phi Epsilon Phi -- or PEP for short. Sam and Alex aren't too interested especially when they discover that Mandy and her equally obnoxious cousin Mindy (whom the girls find out goes to their school) are both PEP hopefuls! As Clover embarks on the pledging process, Sam and Alex start to notice changes in her. She seems to be extremely happy. Abnormally happy. Annoyingly happy. And when other sororities on campus are mysteriously attacked, they begin to grow suspicious of PEP, as well as the pledge pin Clover is wearing. It turns out PEP's president, a student bent on getting revenge against those who rejected her (she pledged ten sororities last semester and never got a bid), is using her evil pins to control her pledges. Her unwitting minions are forced to carry out her evil plan to wipe out all other sororities. Can Sam and Alex stop her before she destroys the other Greeks as well as her pledges¿ or will they too be pinned and become freakishly peppy? In a b-story, the girls each try to find a university activity to join.