As the Greendale year-end paintball extravaganza continues, the game takes a dramatic turn with new intruders arriving on the scene. The study group realizes they must unite to defeat the enemy despite disagreements about strategy.
As the Greendale student body enjoys their year-end picnic, Dean Pelton announces plans for a small, quick, safe game of paintball. As the game heats up, alliances are formed - and broken - and friendships are put to the test. When a mysterious and threatening figure emerges on the Greendale campus, it becomes apparent that this is no ordinary game of paintball. MORE -LESS
Just as the study group are getting ready for their final Anthropology exam, Shirley goes into labor leaving the group to figure out the best way to help. Meanwhile, a riot in the parking lot starts during the World Food Festival.
As the study group assemble their 20th and final diorama for their anthropology class, they reminisce about their favorite moments over the past year. Meanwhile, Troy's monkey reappears but disappears back into the ventilation system, leading Senor Chang to try to get the monkey and retrieve all their stolen loot.
The study group chooses their spring electives. Britta and Troy explore an acting class, and Abed picks a course that studies the 1980s sitcom Who's the Boss?. Meanwhile, Jeff and Pierce take a wine tasting class where they meet a mysterious woman who sweeps Pierce off his feet which raises Jeff's suspicions.
Jeff incorporates Abed's love of cinema and pop culture, into a specially themed "Pulp Fiction" surprise birthday for him. But the tables are turned as Abed arranges another dinner with an unsuspecting Jeff at another eating establishment.
Annie organizes a baby shower for Shirley, while Shirley plots to keep Senor Chang out of her life. Meanwhile, Britta is interested in Abed and Troy's new friend, Lukka, who has a dark past.
Greendale prepares for the Vice President's visit. Dean Pelton organizes the first student elections, putting Annie against Jeff, Pierce, Leonard, and Star-Burns, among others. Meanwhile, Abed develops a friendship with special agent Robin Vohlers.
When Pierce lands in the hospital, he believes he's dying and gives the study group specific gifts that are actually meant to torment them. Britta wonders what to do with a blank check for "charity," Jeff ponders the idea of meeting his father, and Troy gets to meet LeVar Burton, while Abed films the whole thing for a documentary.
Troy and Abed compete for the attentions of the college librarian, while Britta strives to be progressive and befriends a fellow female student whom she believes is gay. Meanwhile, Jeff finds himself reluctantly hosting an impromptu party at his apartment when Professor Duncan invites himself over to watch a soccer match.
Abed invites "Fat Neil" to play a game of Dungeons & Dragons with the rest of the study group, hoping to boost his confidence, after Jeff becomes concerned about him being a loner. When Pierce finds out he was not invited, he joins anyway, disrupting their plans.
Annie convinces the group to put on a middle school anti-drug production, but finds it continually derailed by Pierce's efforts to give himself a better role. Meanwhile, Chang attempts to connect with Shirley, while a prank involving Britta's phone puts Jeff in an awkward situation.
The group members debate whether to add Annieās crush, who recently enrolled at Greendale, or Senor Chang to the group. Shirleyās ex-husband comes back into the picture, and she has big news for everyone.
Abed wakes up in stop-motion animation making him believe that the group must re-discover the true meaning of Christmas. With the help of Professor Duncan, the group explores Abed's winter wonderland and soon discovers the truth behind Abed's madness.
It is Troy's 21st birthday, so the group decides to hit the bars. While Britta and Jeff are drinking too many cocktails, Shirley is taking down incriminating pictures of herself, Annie is embracing her fake identity and Abed gets into a deep conversation with another Sci-Fi lover.
When Dean Pelton starts checking class schedules, he discovers that Jeff has listed a class that doesn't exist. Abed and Troy build an elaborate blanket fort.
Annie's favorite pen goes missing, and she suspects that someone in the group took it. Then study room is put on lock down, and Jeff starts conducting the investigation. Troy and Abed are especially anxious to get out of the room in order to make it to the Greendale Puppy Parade in time.
After a classroom smackdown with a group of "mean girls" led by Meghan, Britta, Shirley, and Annie bond with Abed by turning him into the ultimate "mean girl." Meanwhile, Jeff and Troy embrace a zen-like spirituality under the guidance of a groundskeeper when they come across a secret trampoline on campus. Determined to uncover the source of their new bliss, Pierce ends up taking a disastrous turn on the trampoline and lands in the hospital. MORE -LESS
Pierce and a few other Greendale students ingest a biohazard substance at the school Halloween Party, causing them to exhibit flu-like symptoms and begin turning into zombies. It is up to the rest of the gang to save themselves and the school when Dean Pelton locks them in with the zombie-infected student body.
Shirley asks for Abed's creative input for a religious film; Pierce is recruited by a group of students his age.
Dean Pelton asks the study group to clean and refurbish the Greendale flight simulator. After an accidental launch, Abed must navigate a safe return.
When Pierce's mother dies, the group helps to comfort him. After putting Jeff in the hospital, by one of her class pranks going awry, Professor Bauer takes a leave of absence and Professor Duncan attempts to take over her Anthropology class.
Jeff falls into old habits after reconnecting with Alan (Rob Corddry), a former law firm colleague; Abed, Annie and Troy look for dirt on Alan.
As the new semester begins, the study group gathers to tackle Anthropology 101; Jeff struggles to establish decorum with Britta and Annie; SeƱor Chang decides to enroll as a student so he can join the study group.
