John may find himself home alone over Christmas when he lets his resentment of actor Macaulay Culkin impact the holiday. Meanwhile, Lou learns that his network-host rival is planning a yuletide special to compete with his; and Andre gets mistaken for a puppet.moreless
Dean Pelton lets two designers test their new social networking application at Greendale, leading to a war among the students; Professor Hickey decides to go underground until the battle ends.
Abed sets up a game of "Hot Lava" at the college as a going away present for Troy.
Annie gets Jeff to help her in the hunt for the "Asscrack bandit". One student returns from the dead, while Shirley comes with news of another persons death.
As the study group sets to work on their first big assignment in biology - a terrarium - they are driven to distraction over how they should pair off to do their project. Elsewhere on campus, Chang patrols the school grounds looking for signs of trouble and imagines himself in a noir detective mystery.moreless
Senor Chang settles in with his new job as a Greendale Campus Security Officer, while Britta is dealing with issues of civil disobedience after her friend is taken hostage in a foreign country. Annie is taking part in the Model United Nations competition and asks for help from the group to defeat her "friend" Annie Kim.moreless