"Remedial Chaos Theory" is an episode of the television series "Community", and was first broadcast on October 13, 2011. It was a conceptual episode, letting the narrative device of diverging timelines to show the difficult relationships of the seven main characters of the show. It was well-received by fans and critics, and certain parts of the episode, such as "The Darkest Timeline". Despite its complexity, the episode has one setting (the new apartment of Troy (Donald Glover) and Abed (Danny Pudi) and only features one extra actor besides the main cast (a pizza boy).
Jeff Winger (Joel McHale), Pierce Hawthorne (Chevy Chase), Britta Perry (Gillian Jacobs) and Annie Edison (Alison Brie) all show up to Troy and Abed's house warming party. Shirley Bennett (Yvette Nicole Brown) is already there, making pies (which no one likes). As people sit down to play Yahtzee, the buzzer rings, and someone has to get the pizza. Jeff proposes a roll of the die, with each number representing a member of the group, sitting around the table, going to get the pizza. As the number comes up, the episode than shows seven different stories, depending on who is dispatched. Each member being absent moves the character interaction in a different direction, sometimes subtly, sometimes dramatically. Without third parties present, different members of the seven have different opportunities to show hostility or attraction to each other, with the results ranging from slight changes in character dynamics, to total disaster (in The Darkest Timeline, which is the one where Troy leaves, and a gun goes off and a bottle of rum causes a fire and...).
An astute reader might notice that there are six sides on a die and seven characters: in the final timeline, Abed points out that with seven people at the table, Jeff would never be the one who would have to get the pizza. After Jeff is punished for his would-be trickery by having to get the pizzas, the group relaxes and has fun, leading to the most pleasant result, and with this ending being the "real" one. It seems likely that this is a comment on how the series progressed: at its beginning, the suave and manipulative playboy Jeff was the star of the show, with the other characters being "wacky neighbors". As the show progressed, all seven characters (and actors) became equal in the ensemble. So my take on that is that the show was making a commentary that it had to move away from its focus on a traditional (white, male) "star" to let the characters grow.
On a technical level, the episode was also amazing, because seven different versions of the same events had to be filmed. Characters had to maintain basic continuity of position, action, and dialog, while changing them slightly for each scene (as in Pierce Hawthorne's story of having sex with Eartha Kitt). It is done flawlessly and intensely, with each scene hitting the points it needs to make, in slight different ways.
Also, in "The Darkest Timeline", the group finds themselves injured and insane, and with Abed insisting, in a reference to the Star Trek episode "Mirror, Mirror", that they all have to wear goatees now.
And also also: I have always found the song Roxanne to be annoying, but never in as perfect of a way as this.