The Darkest Timeline is an alternate world envisioned by Abed Nadir which was created by the roll of a die. Created alongside six other timelines it was considered the worst due to a series of unfortunate events which resulted in tragedy within the study group. Its first appearance was in the Season Three episode "Remedial Chaos Theory".
Chain of events
In this particular timeline, Troy races out to get the pizza, shutting the front door very hard on his way out. The force of that causes a part of Abed's Indiana Jones diorama, the boulder, to roll off onto the floor. Shirley leaves the table to check on her pies in the kitchen. Jeff stops Britta from singing, and she goes to the bathroom to light up a joint. Pierce asks Jeff about his father, causing Jeff to get up from the table to get a drink. Jeff hits his head on the ceiling fan, and Annie offers to take a look at his injury in the bathroom. On the way there, Annie trips on the still rolling boulder and falls onto the coffee table.
Pierce's bottle of Serbian rum, which was resting on top of it, goes flying. It crashes, spilling rum all over the floor. After seeing Annie's fall, Pierce quickly stands up to offer assistance and kicks his housewarming present, the Norwegian Troll doll, across the floor. Annie's purse lands on the ground, and the jolt causes the gun inside to discharge and shoot Pierce in the leg. Britta hears the commotion and stumbles out of the bathroom, dropping the joint she was smoking onto the floor. The lighted joint lands on the floor where the Serbian rum is, igniting it and causing a fire to break out. Annie goes to help Pierce as blood sprays out of his wound.
The blood covers Shirley who had just exited the kitchen with her finished pies. Jeff tries to put out the fire while a disoriented Britta runs to the kitchen to get water to help him. Troy then returns with the pizzas. Shocked at the scene in front of him, he notices the Norwegian Troll staring at him, surrounded by flames and the remnants of its burnt box. In the aftermath of these events Pierce has supposedly died from his leg wound, Annie is institutionalized due to her guilt, Jeff lost an arm after trying to put out the fire, Troy severely injured his larynx trying to destroy the Norwegian Troll doll by eating it while it was on fire and Shirley has become an alcoholic.
The only one unscathed was Britta who dyed a streak of blue in her hair which Jeff points out is something she did, not something she experienced. The Abed of that timeline suggests that they somehow find a way to return to the "prime" timeline and replace the study group there. Out of black felt he cuts out black Van Dyke shaped beards and passes them out to the other members. He refers to them as goatees and asks them to wear it as a symbol of their evilness until they can grow a real one. Most of the group rejects this idea, too traumatized by their own fates. However, Troy puts on his felt beard, and he and Abed perform their signature handshake saying, "Evil Troy and Evil Abed".
Crossing into the Prime Timeline
As the groups third year continues, Abed and Troy are shown to be growing distant. When Abed goes into The Dreamatorium by himself, Evil Abed appears to him. Evil Abed begins to subtly influence Abed to further his own agenda ("Contemporary Impressionists"). Sometime later, Star-Burns seemed to have died in a meth-lab explosion and a lawyer missing his right arm delivered his video will to Abed, possibly foreshadowing the arrival of Evil Jeff ("Course Listing Unavailable"). After inciting a riot at school at Star-Burns wake, the group is expelled from Greendale. They all gathers in Troy and Abed's apartment to commiserate which ends up mirroring events from the housewarming party.
Due to the gloomy atmosphere, Shirley contemplates drinking again. When the pizza they ordered arrives, Jeff suggests rolling a die to choose who will get it and once Britta volunteers she is immediately smitten when she sees Toby the pizza guy. Abed wonders if the timeline they are in now is the Darkest Timeline since they have all been kicked out of school. Troy rejects the idea, insisting that they will all survive their expulsion since they're all alive, and they still have each other. Troy's speech raises the spirits of the group, causing Shirley not to drink. After he compliments Britta, she quickly loses interest in Toby and avoids the fate from her timeline ("Course Listing Unavailable").
After the group clears their name and are allowed to return to Greendale, Abed sinks into a depression since Troy was forced to join the Air Conditioning Repair School . Evil Abed appears to take over his body, dons a felt goatee and attempts to recreate The Darkest Timeline. He causes Britta to become depressed causing her to consider dying her hair. Evil Abed gets a bone saw, intending to make the Prime timeline Jeff just like his own one armed Jeff. However, when he encounters Jeff in the courtroom, he finds himself moved by the speech he is giving about friendship and selflessness. Evil Abed's felt beard falls off, and he "leaves" Abed's body ("Introduction to Finality").
The return of the Darkest Timeline
In the study group's fourth year together at Greendale, Jeff throws an eventful Christmas party at his apartment. After exchanging gifts, Abed wonders what is happening now in the Darkest timeline. A montage is then shown featuring Evil Jeff in a courtroom pleading with a judge to release Evil Annie. She had been committed to the Greendale insane asylum for robbery and assault. After he secures her freedom, he and Annie kiss. Jeff then tells her that he and the rest of the group are now plotting the destruction of the "Prime Timeline" ("Intro to Knots").
Towards the end of the school year, Jeff is hesitant about graduating and imagines a scenario where Evil Jeff "crosses" into the prime timeline. Evil Annie is with him who gives him a fake second arm to blend in. Evil Jeff then makes his way to the various members of the study group to sow dissension between them. Only Abed sees through his disguise and Evil Jeff uses a special paintball gun to transport him to the darkest timeline. Once there Abed meets the Abed of that timeline who has renounced his evil ways. With his doppelgänger’s help Abed is sent back to the prime timeline. Meanwhile, Evil Annie finds the original Jeff and attempts to seduce him.
Jeff rebuffs her advances only to be confronted by his evil counterpart who attempts to shoot him. However, Chang jumps in front of paintball bullet and takes the hit allowing Jeff to escape. As Evil Jeff and Annie recuperate the rest of the evil study group then appears. Over at Troy and Abed's apartment, Jeff tries to warn the study group about the duplicate invasion. They are only convinced when Abed returns and demonstrates the Darkest Timeline paintball tech he has with him. He arms his friends with the equipment and they leave for Greendale to face off against their counterparts. Back at school, the Evil Study Group go the cafeteria only to encounter Evil Pierce.
Pierce tells them he faked his own death to teach them all a lesson. Evil Jeff then says the first to shoot themselves will win which Evil Pierce proceeds to do along with Evil Britta. The Prime Timeline study group then makes their presence known and a paintball battle breaks out. Each one takes out their evil counter part until only Evil Jeff is left standing. Abed then reminds Jeff that this is all his imagination and he can make the scenario go anyway he wants. Jeff dodges Evil Jeff's bullet and then shoots him back to the darkest timeline. After his reverie is over, Jeff catches the die he had attempted to roll earlier ("Advanced Introduction to Finality").
Each separate timeline represents the study group's interactions based on the absence of one of its members. When Troy leaves to get the pizza, the worst possible scenario occurs, suggesting that without him in the group, chaos erupts. Jeff's timeline is the complete opposite of this. His controlling nature, in addition to his inability to completely open himself up to the group, means that the best possible scenario occurs in his absence. It can be inferred that Troy is a more passive and calming influence on the group than Jeff whose presence unknowingly stirs up conflict. Yet at the same time this timeline recognizes that Jeff serves as a focal point to the group, as even through their disapproval of and dealings with him they became more unreserved and open with each other.
When NBC announced their mid-season schedule for 2012, it was revealed that "Community" would not immediately return and was instead put on hiatus to come back sometime at a later date. This was done to make room for the returning "30 Rock" to take its 8:00PM EST time slot and to also move the new show "Up All Night" to Thursday from its Wednesday slot. Fans of Community immediately began to refer to the hiatus as "The Darkest Timeline". Many of them began internet campaigns championing the show and demonstrating their support on social network sites with the rallying cry being #sixseasonsandamovie. On February 21, 2012, NBC made the announcement that "Community" would be returning March 15th to its regular time slot at 8:00PM. When it returned, it had a 2.2/7 ratings among the 18-49 demographic, its highest ratings since Season One.
The Darkest Timeline is symbolized by black Van Dyke shaped beards which is a direct reference to the "Mirror Universe" concept in Star Trek first introduced in the episode "Mirror, Mirror". In the story, evil versions of the main characters exist in an alternate reality and that version of Spock is sporting a Van Dyke beard, often colloquially referred to as a goatee.