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 CSI team investigate the murder of a man whose daughter was killed five years ago, and the bizarre death of a young man who appears to have been killed by a T-Rex.

A documentary crew visits the hospital six months after the shooting to document the road to recovery for doctors and patients; Meredith helps Cristina put on a brave face for the cameras.

The gang gets a real scare after Dee reveals she's pregnant, forcing the guys to recall their last hazy Halloween party to determine who the father is.

Episode info coming soon ..

Leonard keeps an affair a secret from Sheldon, Howard and Raj.

The McRib returns on election day, and Maira Kalman falls in love with Abraham Lincoln.

Episode info coming soon ..

Kevin convinces everyone to come to the suburbs for Halloween. Meanwhile, Pete has given Ruxin the privilege of selecting his opponent's team for their upcoming match. Taco feels responsible for events relating to a petting-zoo monkey.

The case of a murder and missing person on a secure compound perplexes the CBI team.

When Darryl takes an idea to corporate over his head, Michael freaks out. Everyone in the office is in a competitive mood as the Halloween costume contest gets underway. Meanwhile, Pam tries to get the truth out of Danny about their dating history.

When Ryan decides his next great endeavor is a scary slasher movie, Kelly Kapoor, Erin, Kevin, Meredith, Creed, and Gabe all pitch in.

Stefan and Damon decide on a new plan to deal with Katherine at the Lockwood’s masquerade ball. Katherine calls on an old friend, Lucy, to attend the ball with her. Bonnie, Jeremy and Alaric all do what they can to help Stefan and Damon, but Katherine has a surprise planned that none of them could foresee. Things take an ugly turn when Matt and Tyler start doing shots with their friends.