Season 4

History 101
When there is a mix-up with a history class registration, Dean Pelton institutes an elaborate physical competition for class space. Meanwhile, Britta helps Abed deal with the anxiety he is experiencing over the thought of the study group graduating and breaking up.
Air Date February 7, 2013
Paranormal Parentage
On Halloween, Pierce accidentally locks himself in his panic room, forcing the gang to search through his house to find the code that unlocks the door.
Air Date February 14, 2013
Conventions of Space and Time
The study group goes to the annual Inspector Spacetime Convention; Annie enjoys the luxuries of the hotel; Jeff spends time with an Inspector Spacetime fan (Tricia Helfer) in the bar.
Air Date February 21, 2013
Alternative History of the German Invasion
The study group starts its European history class with professor Noel Cornwallis (Malcolm McDowell); Dean Pelton is upset when Chang returns to campus.
Air Date February 28, 2013
Cooperative Escapism in Familial Relations
The study group goes to Shirley's house for Thanksgiving dinner; Jeff reunites with his father, who he hasn't seen since he was young.
Air Date March 7, 2013
Advanced Documentary Filmmaking
Abed makes a documentary about Changnesia in order to receive a grant, with Jeff attempting to prove Chang is faking his disease.
Air Date March 14, 2013
Economics of Marine Biology
Dean Pelton enlists the help of the study group in order to enrol a wealthy new student whose laziness is expected to bring much needed funds to Greendale.
Air Date March 21, 2013
Herstory of Dance
When Dean Pelton plans a Sadie Hawkins dance, Britta throws a Sophie B. Hawkins dance in protest. At the dance Abed goes on two dates, each set up by Annie and Shirley.
Air Date April 4, 2013
Intro to Felt Surrogacy
When the study group's balloon ride crashes in the wilderness, the friends encounter a mountain man.
Air Date April 11, 2013
Intro to Knots
The episode features the study group gathering around for Christmas at Jeff's apartment as they try to convince their history professor to change their grade. Malcolm McDowell guest-stars as Professor Cornwallis.
Air Date April 18, 2013
Basic Human Anatomy
In this episode, Troy and Abed switch bodies - an homage of Freaky Friday - while the valedictorian race between Annie and Shirley sees the pair team up to take down Leonard who is currently #1 in the class.
Air Date April 25, 2013
Heroic Origins
In this episode, Abed pieces together the past timelines of the group to show their lives have always been intertwined.
Air Date May 2, 2013
Advanced Introduction to Finality
With enough credits to graduate, Jeff contemplates his future. The study group once again is faced with the darkest timeline.
Air Date May 9, 2013