On a hot sunny day, Ilana hunts for a good last-minute gift for her sex buddy Lincoln, having only found out his birthday on the day itself. Male Stacy (Seth Rogen) falls asleep during woman on top sex with Abbi. The girls look for an air conditioner for Abbi's bedroom – and steal one from a dormitory at their old university, NYU. Abbi's roommate Melody's boyfriend Bevers brings a box of kittens to Abbi's apartment. One of them escapes and startles Stacy while he is kissing Abbi in her bedroom – causing Stacy to accidentally push the air conditioning unit out of the window.

Abbi is horrified that Bevers has spent so long on her and Melody's couch that he has a large bedsore on his lower back; Melody is in Port-au-Prince.

Abbi is finally able to help her boss Trey to train someone at Soulstice, the gym that Abbi cleans at. Unfortunately, the new client is obese Bevers – who has decided to get into shape. The training goes wrong when Bevers is injured while falling off a treadmill and decides not to return.

Ilana becomes a life model at Abbi's art class. Abbi finds it distracting to see her nude.

Abbi, Ilana and Ilana's mother Bobbi (Susie Essman) have their nails done. Abbi goes to Jeremy's apartment for a casual date. During missionary sex, Abbi suggests that they switch. She meant to change position, and is surprised when Jeremy expects her to peg him using his strap-on dildo. Abbi phones Ilana for advice while Ilana and Bobbi are buying counterfeit designer handbags from a Chinese woman. Ilana is delighted that Abbi has the opportunity to peg and encourages her to do it, which she does. Ilana and Bobbi go to Bobbi's mother Esther's shiva, where Ilana's father Arthur (Bob Balaban) and her brother Eliot are already attending. Abbi arrives at the shiva, where she talks to Ilana and her family about pegging. After Ilana and Bobbi leave, they are arrested by the police, who seize their bags before releasing Ilana and Bobbi. Abbi washes the dildo in Jeremy's dishwasher, which melts it badly out of shape. Abbi buys a new dildo of similar appearance from a sex shop. Jeremy rejects the replacement, due to it being a knockoff. They argue – she tells him that he is too particular and he says that she is judgemental and has bad taste – then Abbi leaves. In Abbi's apartment, her dildo is fixed to the wall and she is using it to hang her necklaces on. She has decided to master regular sex and rejects Ilana's suggestion to peg her. At Ilana's parents' house, Bobbi convinces Arthur to buy a dildo so that she can peg him.

Abbi has her nose pierced.

Ilana feels that she is missing out on a lot of fun. She goes into work to tell them that she is leaving straight away because she is going to a party.

Abbi and Ilana go to a party at Trey's apartment, but Ilana finds it boring, so they leave – Abbi falsely claims to Trey that she has to leave because she has a tapeworm in her butt. They attend two more parties which they also leave because Ilana thinks they are boring. The next party is much more lively, but the police stop the party, so they leave. They go to a jazz nightclub, where Ilana discovers Abbi's drunken alter-ego, jazz singer Val. They leave at 6.45am.

Abbi, Ilana and Lincoln are invited to the wedding of Eliot's dog to his partner's dog in Central Park later in the day. Feeling sucked into a never-ending web of technology, Abbi and Ilana unplug to go rollerblading in Central Park without their cellphones. While there, Abbi falls into a hole, is injured and is unable to climb out. Ilana searches for help for her, as well as to find out exactly where the dog wedding is taking place. Ilana arrives at the dog wedding as it is taking place. The attendees halt the proceedings to get medical help for Abbi. The group, including Abbi on a stretcher, go back to finish the wedding – before she is taken away by the paramedics.

While masturbating and watching porn on her laptop, Ilana discovers that Abbi's boss Trey used to be a solo porn performer named Kirk Steele. Abbi applies for a menial job in a bar, and is quickly rejected. Ilana babysits a little boy, Oliver, for his rich Manhattan mother. Ilana brings Oliver to a café, where she meets Abbi and shows her the porn. Abbi uses this information – with Ilana's encouragement – to blackmail Trey into letting her teach the kettlebell class that day. At the beginning of the class, Abbi accidentally throws a kettlebell at a large $1400 mirror, severely damaging it. This means that Trey and Abbi have to come up with $700 each to buy a replacement mirror so that they can pretend that the breakage did not happen and avoid being fired. Oliver suggests to his mother that Ilana take the designer clothes to a homeless shelter that his mother was going to give to horses. Oliver then tells Ilana that the real plan is to take them to a clothes shop to sell them. Ilana and Abbi sell the clothes for $903. Trey and Abbi replace the mirror that night. He lets Abbi teach another class (which does not involve weights) in the morning, because the instructor is missing.

Abbi and Ilana are working coat check at a party. Ilana sees her doppelgänger Adele (Alia Shawkat), and is immediately strongly attracted to her, without noticing their physical similarity. Ilana leaves Abbi alone in the cloakroom. Abbi accidentally gives Kelly Ripa's coat to someone else. Abbi hopes that bringing Kelly her coat will lead to her forming a friendship with her. Abbi goes to the address that is on a card in the pocket of the only remaining coat in the cloakroom. At that apartment, the resident is holding an orgy and tells her that it belongs to her ex (David Wain). The resident hands Abbi some of her ex's belongings to take to him. Abbi goes to the man's apartment and gives him his coat and the things that his ex handed her. Abbi's plan is successful, and she goes to Kelly's apartment. Abbi is disappointed to learn that Kelly is not as glamorous as she seems to be on television. Abbi leaves after two male escorts arrive. Ilana is enjoying her fling, until she is surprised when Abbi points out to her that Adele looks exactly like her. Knowing of the strong physical similarity makes Ilana feel uncomfortable. Ilana makes Adele leave her apartment and decides to not see her again when she finds out that she does not smoke marijuana.

The girls celebrate Ilana's 23rd birthday by going to a restaurant on St. Mark's, Manhattan. On the way, they see a man who is walking on stilts and dressed as a tree. They encounter two loud acquaintances whom they dislike, and who push their table next to Abbi and Ilana's. Because of that, Abbi and Ilana leave after drinking wine, without ordering any food.

The girls go to a stall where Ilana buys a wig and they buy a T-shirt each, which they wear. Abbi's shirt has a picture of a challah and says Challah Back on it; Ilana's says Female Body Inspector. A mugger snatches a bag out of Abbi's hand. The girls chase him on foot, Ilana's wig dropping to the ground. They see him go into his upmarket house, where his mother is hosting a dinner party. She calls upstairs to her 34-year-old son Timothy, who argues with her and throws Abbi's bag downstairs. After leaving the house, 'tree man' gives Ilana her wig.

The girls sit on the steps outside a restaurant and eat pizza. They talk to each other about their accomplishments during the past 12 months and their plans for the next 12.

The girls play basketball against a group of little boys.

Ilana buys groceries from the food cooperative that she is a member of. She is told by the staff that today is the last day on which she can work her shift in order to maintain her membership. Ilana cannot do the shift because she has an appointment, so she asks Abbi to pose as her while working the necessary hours. Abbi does so, while wearing Ilana's clothes as well as talking and acting like her. During the shift, Abbi is attracted to Craig and reveals her identity to him. He is angry with her and informs the branch manager, who bans both girls for life.

Abbi leads an exercise class of elderly people in Soulstice's swimming pool. An elderly man pretends to have lost consciousness in the pool in order to receive mouth-to-mouth resuscitation from her.

Abbi prepares for her first "Soulstice Games" in Central Park since being promoted from cleaner to trainer. Ilana leaves work to try to discourage Abbi from competing, but Abbi knocks fellow trainer Gemma to the ground with a pugil stick then pummels her face with it. Trey assumes that she started steroids after being promoted, saying that every new trainer does.

Ilana and Jaimé spend all their rent money ($400) on an exterminator to kill a rat that is in their apartment. They decide to throw a party and charge an entry fee of $10 in order to make back their money. A basket of food and drink arrives on their doorstep, which Jaimé assumes is a gift from his parents. Abbi joins Tinder after Trey drunkenly kisses her at the Summer Solstice Soulstice Party. Ilana and Jaimé's party becomes more successful when Jaimé convinces Abbi to invite her matches from Tinder. Ilana tries to track down a rat in her apartment that the exterminator failed to kill – while trying to prevent the guests discovering it. Several men show up to the party because Abbi did not realize she had the option to "swipe left" and reject guys. Trey flirts with Abbi through texting and she hides it from Ilana. Ilana takes the cat from the bodega to hunt down the rat. A courier calls at the apartment to say that he needs the basket, as he accidentally delivered it to the wrong address. Abbi makes out with him while Ilana and Lincoln put things in the basket to make it look like it was when it was delivered to them. Ilana finds the rat and its young in the basket – which delights her and disgusts the guests. Abbi tells the courier to report that the basket was stolen, then she pushes him out of the door. Two more rats walk across the floor.

Abbi and Ilana sit on a bench in a park and talk about their ideas for inventions. Behind them, two people fall down steps and one is taken away on a gurney.

Abbi gives a cup of her urine to Ilana which she intends to pass off as her own at a urine test. Seconds later, Ilana collides with another pedestrian, spilling it.

Abbi and Ilana escort patients through a protest outside an abortion clinic.

Ilana starts a new job as a waitress at a trendy restaurant in Manhattan called Sushi Mambeaux. The staff and the boss Marcel (RuPaul) frequently insult people.

Abbi and Ilana Heimlich a choking man through the railings of Gramercy Park, but he will not let them in the park.

Abbi fabricates a relationship out of her meaningless six-day fling with Mike. She ends her delusion after her attempt to give advice to an unhappy wife ends with her laughing at Abbi and Mike telling her during a phone call that he has been having sex with two other people during their fling.

Ilana house sits for the Strands when they go to the Hamptons. She invites Jaimé and Lincoln to their palatial house. Jaimé was circumcised recently and has to avoid getting an erection while his penis heals. Ilana and Lincoln define their relationship as boyfriend and girlfriend. Abbi finds her high school English teacher Mr. Miller (Mike Birbiglia) on Bumble and invites him to the house. After he arrives, she and he tell each other that they were attracted to each other when he taught her. Abbi decides not to have sex with Mr. Miller, because she finds it creepy that he wants to roleplay that she is 17. The tumble dryer catches fire, then they all go outside and the FDNY put it out.

Ilana goes to what she thinks is a job interview for an office manager position, but she is at the wrong address and the two men she is talking to are managers of a YouWork centre and think she is there to rent an office. Ilana puts furniture in the street and charges smokers to use it, calling her business SheWork. The YouWork managers tell Ilana to close SheWork and give her $500 to do so. She tells all her customers to leave because the business is closing.

Bobbi takes Ilana and Abbi shopping for bras.

Ilana remembers that she bought some bitcoins several years ago with her then lover. She finds him, and he gives her $8,265 - the value of her share of their bitcoin.

Abbi takes her laundry to a laundromat; they lose a sweatshirt of hers which she is fond of. She puts up posters of herself in the sweatshirt in order to try to recover it. She is reported as missing on TV, so she phones a TV channel to tell them that she was never missing. The sweatshirt is handed in to the laundromat, who give it to Abbi.

Abbi asks her manager Lisa if she may organise the window display at Anthropologie. She is disappointed when Lisa says no. Abbi goes ahead without permission and as a result is fired and banned from all branches of the chain.

Ilana goes into Jaimé's room for the first time ever because of a bad smell from there. She is horrified to see that he is a hoarder. She later talks to him in front of his boyfriend Johnny and Abbi. Jaimé says that he is going to move in with Johnny in Montclair, New Jersey.

Ilana is delighted to discover that she is distantly related to a 91-year-old Holocaust survivor, Saul who lives in Manhattan. She and Ilana visit him at his rest home and sneak him out to take him shopping at his request. Abbi and Ilana are delighted to see Alan Cumming, but Saul has not heard of him. They follow Cumming to a drag brunch. While Abbi and Ilana are talking to Cumming, Saul boards a bus. The girls go to the home to tell the receptionist that they lost him. She angrily informs them that he always goes to IKEA when he gets out, and tells them to bring him back. The girls go to IKEA and find him shopping there.

Lesley gives Abbi a bright yellow hat, which she wears despite her, Ilana and Saul disliking it. After wearing it all day, she tells Lesley that she dislikes it and Lesley accepts that she need not wear it.

Ilana is delighted to be accepted into Hunter College as well as being recruited as for a modelling shoot. She develops severe conjunctivitis, which prevents her from doing the shoot, which Bobbi does instead. Ilana does not have a doctor in NYC, so she goes to her vet acquaintance's surgery to receive a hepatitis B vaccine. Lesley ends her fling with Abbi, saying that Abbi is not an adult yet and that Abbi's life is a series of wild shenanigans. Hurt by the break up (by the reality of what Lesley said) and encouraged by a different friend, Abbi applies for an artist residency in Colorado.

Abbi, Ilana and Bevers sell some of Abbi's things on the street. They decide to keep one of the items, the couch. However, the garbage truck takes it away, so the girls jump on the back of it and retrieve it from the depot. They leave it outside a Lil Wayne concert, in order to take it home afterwards. They take an MDMA pill each and are rejected due to the tickets they bought on Craigslist being counterfeit. They try to find a way to sneak into the concert. On the journey home, they realise that they forgot the couch. Bevers tells Abbi that he sold everything, but he actually has a lot of it in his room.

Abbi and Ilana set out a mission to get Abbi's last bodega bacon, egg, and cheese sandwich before moving. They fail to find one before bodegas stop selling them at 11AM. Ilana finds a valuable toilet on the street; she and Abbi roll it on a skateboard towards Ilana's apartment. When they stop to talk on the Brooklyn Bridge, Ilana and Abbi reflect on their friendship. Ilana becomes emotional and says her "final goodbye" to Abbi. When Ilana leaves the toilet for Abbi to keep, it is taken.

Ilana organises a party on the roof of her apartment building, attended by several people who know them, as well as some of Abbi's neighbors.