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.

The episode was rated 8.32 from 1400 votes.

When Chang gains control of Greendale's campus, the study group forms a plot to take back the school. Troy seeks help at the Air Conditioning Repair Annex.

The episode was rated 8.32 from 1272 votes.

Abed becomes convinced that there is a conspiracy afoot and that Dean Pelton is an imposter. When Abed is apprehended sneaking around on campus, he is required to see a therapist, or risk being sent to jail.

The episode was rated 8.33 from 1284 votes.

The group becomes popular when they start a racket in chicken fingers.Their new-found popularity inflates their egos, and Jeff realizes that he must find a way to end his friends' reign.

The episode was rated 8.36 from 1383 votes.

Jeff shows a little leg in billiards class when he's forced to wear the Greendale PE uniform, while the gang tries to help Abed get a girl.

The episode was rated 8.37 from 1381 votes.

Abed plans an epic going-away party as Troy prepares to leave Greendale; a fun game transforms into a high-stakes competition.

The episode was rated 8.44 from 1825 votes.

The war between Abed and Troy intensifies, prompting Jeff to try to negotiate a truce between the former best friends while the rest of the group choose sides.

The episode was rated 8.50 from 1411 votes.

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.

The episode was rated 8.55 from 1417 votes.

In a homage to Law & Order, the study group investigate a crime when someone sabotages their science experiment. When they discover the perp, Annie plans on prosecuting them to the fullest extent of Greendale's Code of Conduct.

The episode was rated 8.57 from 1341 votes.

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.

The episode was rated 8.66 from 1484 votes.

Pierce is summoned to Hawthorne Enterprises to discuss his inheritance with his deceased father's former right-hand man, Gilbert Lawson. The study group goes with him for moral support and must all pitch in to play the video game of their life on Pierce's behalf for the sake of his inheritance.

The episode was rated 8.72 from 1425 votes.

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.

The episode was rated 8.78 from 1445 votes.

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.

The episode was rated 8.83 from 1372 votes.

New roommates Troy and Abed host an apartment-warming party that takes a strange turn.

The episode was rated 8.85 from 1563 votes.

The sexual tension between Jeff and Britta becomes a hot topic in study group. A contest for a chance at early class registration turns the peaceful campus of Greendale Community College into an all-out war zone.

The episode was rated 8.98 from 1662 votes.