Dean Pelton lets two designers test their new social networking application at Greendale, leading to a war among the students; Professor Hickey decides to go underground until the battle ends.
Jeff helps Duncan pursue Britta.
Abed sets up a game of "Hot Lava" at the college as a going away present for Troy.
After Pierce Hawthorne's funeral, the gang retires to the study room. They are surprised with a communal polygraph test by Pierce's attorney to prove themselves innocent of his murder. They are individually quizzed in an effort to prove their involvement of the potential crime.
Jeff returns to Greendale a year after graduation on a mission. He meets the rest of the group and finds out what has happened to them since graduation.
Annie gets Jeff to help her in the hunt for the "Asscrack bandit". One student returns from the dead, while Shirley comes with news of another persons death.
Annie and Professor Hickey work the Greendale bureaucracy to get a bulletin board back on the wall. Jeff, Chang, Shirley and Professor Duncan discover the challenges of planning a school dance.
Jeff starts his position as a teacher. Abed gets the rest of the group to take a class about Nicolas Cage.