The gang celebrates Troy's birthday with party hats and an ambiguous holiday cake. Troy's a Jehovah's Witness and doesn't celebrate holidays of any type, so the gang is trying to be sensitive to his beliefs but wants him to feel loved. Annie reads some facts about Troy's birthday to the group. When she suggests that on the Chinese calendar he's a horse, Troy corrects her and says he's actually a snake. Annie assumed he was born in 1990 like she was, but Troy corrects her again; he was born in 1989. Jeff states the obvious. Troy isn't turning 20; he's turning 21, as in the legal drinking age. The lame party around the study group table just became unacceptable.
Jeff and Britta argue over which bar to take Troy to for his first official and legal drink. After going back and forth, they finally settle on Flannigan's Hole. Just as everyone gets ready to leave, Annie makes it a point that she's only 19 and can't get into a bar. Britta agrees to give her a fake ID to use for the night. Annie, resistant at first, finally agrees. On the way to the bar, Jeff discovers Flannigan's Hole is closed. He calls Britta, who is in the car with Shirley and Annie. Since Flannigan's Hole is closed, they agree to go to Ballroom, another bar in town, instead. Shirley seems unsettled when Britta tells her the change in plans, but goes along anyway.
Troy gets into the bar first, followed by Jeff and Abed. The girls arrive next. Annie has decided to take on the identity of the woman from her fake ID. Caroline Decker is from Corpus Christi, Texas and Annie makes sure to use a strong Southern accent despite Britta's advice to the contrary. Shirley walks up to the bouncer after Britta and Annie have entered the bar. He greets Shirley like an old friend, it's nice to see her, and it'd been a while. Shirley gives him a look and then tells him that he doesn't know her.
The gang gathers at a table to order drinks. The walls are covered with photos of what appear to be the bar regulars. Just as the waitress approaches the table to take their orders, Shirley spots a drunken photo of herself on the wall directly behind where they are sitting. She discreetly removes it from the wall. Everyone orders a drink except for Troy, who is waiting until midnight for his first official drink. Jeff orders a scotch, and Britta orders vodka with olives - each trying to prove they are more sophisticated than the other. Annie orders water, but complicates it by taking on a Texan persona and giving the waitress a full back story of her life, well… Caroline Decker's life. Britta reminds her that they are already inside the bar; she doesn't need to show her ID anymore. While they wait for their drinks, Shirley decides to take a walk around and get familiar with the bar, as a way to hunt for other pictures. Annie does the same, but heads up to the bar. Abed spots a video game and heads over to play that.
Abed is playing the video game when a bar patron approaches him. He offers to buy Abed a drink while they talk about video games and other common interests. Pierce finally shows up to the bar, but struggles to get through the door in his wheelchair. He refuses to take help from the bouncer. Annie is sitting at the bar, chatting with the bartender and expanding on her fictitious life as Caroline Decker from Corpus Christi. Back at the table Jeff and Britta are giving Troy advice on what drink to order at midnight. Jeff and Britta are still arguing over two bars in town that they have differing opinions on.
Abed is talking to the video game guy at the bar when the guys asks Abed to teleport their conversation to some place more private. Abed brushes it off. Down the bar, Annie is still talking to the bartender and eventually orders a screwdriver, ditching her root beers. While Annie downs her screwdriver, Abed continues his conversation. The video guy, who finally introduces himself to Abed as Robert, asks if Abed would like to have sex with him. Abed turns him down. He says he knows Robert was hitting on him, but he liked talking about Farscape, the Australian-America science fiction television series, too much to end the conversation. Robert throws his drink at Abed and leaves.
Pierce is still trying to get into the bar when his wheelchair battery dies. Now he's stuck. Shirley has collected quite a handful of photographs when she bumps into Jeff, Troy and Britta. Thinking she got all the photos, Britta whips out one she found in the bathroom. Shirley gets angry, takes the photo from Britta and leaves the bar. One her way out, Shirley runs into Pierce, who is stuck in the doorway. He finally asks for help.
Just before midnight, Troy finally orders his first drink, a 7&7. But before he can enjoy it, he helps a drunk Britta and Jeff to the car, followed by Annie and Abed. Troy piles Jeff, Britta and Abed into the back of Jeff's car. Annie gets into the front seat with Troy at the wheel. On the road, Jeff and Britta realize that the bar they have been fighting over all night is actually the same bar. Troy can't believe this revelation.
Troy walks Annie to her front door to make sure she gets in safely. When he gets back to the car, Jeff and Britta are making out in the backseat with Abed sitting next to them. Troy realizes he might be the most adult of all of them.