Ross breaks up with Bonnie in order to get back with Rachel, who prompts him to first read her 18-page letter discussing their relationship and previous break-up. Ross falls asleep while reading the letter, and unwittingly agrees to take full responsibility for their break-up later on. Ross and Rachel then break up again after he refuses to take all the blame for their previous problems (as have been stated in the letter) and insists they were "on a break".

Monica runs into Chip Matthews, Rachel's high school prom date, and is thrilled when he asks her out, though it causes tensions between her and Rachel (and ultimately Ross). Monica quickly realizes Chip never matured beyond high school and dumps him. Chandler forces Joey to sell the entertainment unit that Joey built after Chandler keeps ripping his work suit on it.

Joey is enticed when a door-to-door encyclopedia salesman shows up at his apartment, since he has always felt left out whenever the gang has intellectual conversations. However, Joey can only afford to buy the sample volume and becomes knowledgeable only on subjects that start with the letter "V." Monica caters a party for her mother, but the mini-quiches are effectively ruined when one of her false fingernails gets lost in one.

Phoebe struggles to remain professional with an attractive client. When she finally confesses her feelings to him, he reciprocates and the two start making out. Phoebe’s boss then walks in on them, informs her the man is married, and then fires her for “being a whore”. Chandler hits a snag whenever he tries to revoke his gym membership due to pressure from the assertive staff, so he enlists Ross's help.

Phoebe has a cold that she thinks improves her singing voice, only to be frustrated when her "sexy phlegm" disappears. She then desperately tries to catch a cold again from multiple sources, including Monica and Gunther, in order to get her “sexy” voice back. Ross attempts to make Rachel jealous by dating Amanda, a beautiful woman with a child Ben's age, only to discover that she just acknowledges him as a babysitter to her child.

Phoebe helps Monica cater a funeral, but the merry widow intimidates Monica to avoid paying. Phoebe then takes charge and demands the widow to settle the bill. Both girls ultimately decide to start their own catering business. Chandler reluctantly helps Joey find Kathy a birthday present better than the one he bought for her (a limited edition book from Kathy’s childhood), ultimately sacrificing his gift to substitute for Joey's tacky one (a dual-functioning pen).

Ross starts playing the keyboards again after much prompting from Phoebe. His musical compositions leave the gang aghast, except for Phoebe who thinks they are brilliant. Chandler's feelings towards Kathy reach a breaking point after they kiss. Guilt-ridden, he eventually tells Joey the truth and then vainly tries to fix things but to no avail.

During Thanksgiving dinner, Joey punishes Chandler for kissing Kathy by sentencing him to a “time out" inside a crate, for the same duration as when Joey was stuck in the entertainment unit in an earlier episode. Joey finally relents when he witnesses Kathy breaking up with Chandler, who is still inside the crate and resists responding in spite of the situation.

Monica and Phoebe buy a tacky van for their new catering business, but plans are upended when Monica is offered the head chef job at “Alessandro's”, a restaurant she recently trashed in a review for a neighborhood paper. Rachel applies for an assistant buyer job in another Bloomingdale's department, only to be sabotaged during the interview by her boss, Joanna, who wants to keep Rachel as her assistant.

Chandler's attempt to set Rachel up with someone from work gets out of hand when his colleagues start competing with one another, believing she only wants a fling. He then scares everyone off by saying Rachel wants a serious relationship. Monica's new staff at Alessandro's resent her for replacing their family member as the head chef, and constantly bully her at work.

Chandler has not had sex with his girlfriend, Kathy, ever since they got together due to the former’s fear of not being able to “fill Joey’s shoes”. Monica and Rachel then offer Chandler some advice on improving his bedroom performance, leading to Kathy expressing her endless gratitude to Monica. Ross lands Joey a job as a tour guide at the museum, which ultimately results in the latter’s disappointment when he witnesses an existential class divide within the museum.

Rachel and Monica demand that Chandler and Joey get rid of their pet birds when the rooster starts to crow incessantly every morning before sunrise. The four of them also have an argument about who knows whom better, which results in Ross designing a trivia quiz with high stakes: if the men lose, they give up their pets, but if the women lose, they switch apartments with the men.

Monica is determined to continue being 'the hostess' and strives to succeed despite having switched apartments with Chandler and Joey. Chandler is worried when Kathy and a fellow actor, Nick, get steamy on stage in a play, which leads to him unfairly accusing Kathy of cheating on him. When he later goes to her apartment to apologize, he discovers that Kathy has started sleeping with Nick, even though the latter two did not when Chandler confronted Kathy about her possible infidelity.

Chandler is depressed over his break-up with Kathy, leading to the girls intervening to help him get over the latter. One of the plans involves bringing Chandler to a strip club. However, the plan backfires when the girls inadvertently sideline him. With no other options, Rachel asks for Ross's help after she accidentally becomes double-booked with Joshua and her boss, with the former inviting her to an inaugural club opening and the latter wanting her to accompany his niece, Emily, to an opera concert.

Ross risks life and limb in his desperate attempt to prove to Emily how tough he is by playing an aggressive game of rugby with her athletic British friends. Monica becomes obsessed with a wall switch in her current (previously Chandler’s and Joey’s) apartment which appears to have no function. She resorts to every possible measure in trying to determine the switch’s origin, but to no avail, so she eventually gives up.

Phoebe’s pregnancy causes her to crave meat despite being a devout vegetarian. She seeks Joey for advice and he decides to sacrifice his meat consumption in order to balance out the amount of meat that Phoebe eats. Meanwhile, Ross wants to spend as much time with Emily as possible before she returns to London.

Phoebe is shocked when she learns that she is expecting triplets and wants to find ways to help financially support her brother and sister-in-law. She ultimately decides to start a massage/taxi business with Frank Jr. using the van that the former and Monica were once going to use for a catering business.

Frank Jr. and Alice ask Phoebe to name one of their unborn triplets, which leads to Joey and Chandler competing to get her to choose their names. In the process, Joey argues that "Chandler" is a sissy name, prompting Chandler to consider changing his full name, though he has ulterior motives. Ross becomes paranoid when Emily and Carol's wife, Susan, spend time together in London, fearing that Susan would once again steal someone he loves.

Monica and Rachel resort to desperate measures in order to win their apartment back from Joey and Chandler. These include bribing the guys with Knicks tickets and challenging them to another game. The girls lose the tickets and the game, but eventually switch apartments while Joey and Chandler are at the game.

Chandler, frustrated by Joey's loud snoring, takes him to a sleep clinic, where he meets an attractive woman with her own sleeping issues. Monica and Phoebe pick up Emily's wedding gown at the bridal shop. Monica tries it on and refuses to take it off. She even resorts to wearing the gown at home while doing chores.

A pregnant Phoebe is frustrated that she is unable to attend Ross's and Emily’s wedding in London. Meanwhile, Ross surprises Emily by inviting Rachel, causing him to reminisce about their time together. Rachel ponders the invitation while also reminiscing about her relationship with Ross. She concludes it will be too heartbreaking to attend the wedding and ultimately decides to stay with Phoebe in New York.

Rachel and Monica throw a baby shower for Phoebe, who is experiencing extreme mood swings and growing depressed about having to give up the babies after they are born. Meanwhile, Ross chooses Joey over Chandler to be his best man, but Joey accidentally loses the wedding ring after throwing a bachelor party for Ross, which features a stripper.

Everyone except Rachel and Phoebe fly to London for Ross’s and Emily's wedding. Joey embarrasses Chandler while sightseeing in London. Ross and Emily are shocked that their wedding venue is undergoing an early demolition. Monica suggests postponing the wedding, infuriating Ross. Back in New York, Phoebe sheds light on Rachel about the latter still loving Ross, prompting Rachel to head to London and stop the wedding by confessing to Ross.

Everyone except Rachel and Phoebe fly to London for Ross’s and Emily's wedding. Joey embarrasses Chandler while sightseeing in London. Ross and Emily are shocked that their wedding venue is undergoing an early demolition. Monica suggests postponing the wedding, infuriating Ross. Back in New York, Phoebe sheds light on Rachel about the latter still loving Ross, prompting Rachel to head to London and stop the wedding by confessing to Ross.