The hyped Apollo 13 episode
"Basic Rocket Science" October 14, 2010
Dean Pelton gets a flight simulator for Greendale after another college is planning on getting their own. He enlists the study group to clean and refurbish the simulator. As the group (with the exception of Abed) wash the simulator, they accidentally launch it, sending everyone into "outer space." Abed is left behind and tries to navigate a safe "return" for everyone.
"Messianic Myths and Ancient Peoples" October 21, 2010
Shirley gets inspired to create a religious film and asks Abed for his creative input only to discover that he wants to make one of his own. Pierce comes to terms with being the oldest member of the group and is recruited by another set of students his own age.
To get everyone in the mood for The Walking Dead... It will air 830/730c, a Shrek Halloween special will air before it.
"Epidemiology" October 28, 2010
Pierce and a few other Greendale students ingest a bio-hazard substance at the school Halloween Party, causing them to exhibit flu-like symptoms and they soon 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.