After Deb's confession to have slept with Keith, Karen shows her the door and later has a misunderstanding which makes her break up with Andy. Haley chickens out on her music career at the last minute, so Chris leaves alone. When she gets home, her older sister Taylor is there. Nathan hopes she won't remember she was his first sex partner at a party in the beach house. They become friends and he decides she can stay a few weeks. Jake is back, without Jenny, for a few days he spends mainly with Peyton. Lucas finds out how Jules' poverty drove her to break Keith's heart. Felix has a fight with Lucas for 'hurting Anna' -who later confesses to Lucas she's just lesbian but hoped to be bi. Karen and Andy ultimately make up.

Karen decides to make Lucas's life as miserable as possible till he takes the heart test and asks Andy over while his house is in a contractor's hands. Brooke needs a job- the Crab shack hires her, but not as waitress, just 'PR' in a crab suit; she quickly makes friends with the other underpaid girls but is the only one to develop a militant labor union attitude. Lucas confronts Dan about Jules, and is told about Debs adultery with Keith, who cannot deny it and swears Jules is his true love. Taylor sees Haley's tattoo and bugs her and Nathan about not following big sister's own advice in the past; when Nathan warns her to stop hinting at their first night she bitches back the full truth can hurt him more- so he tells Haley himself, who needs a cooling off period but then understands it was before they knew each-other; all three make up. Lucas confides about Jules to Anna, now he knows her lesbian secret. Keith offers Luke to take the HCM-test together, now Jules wants him to. Dan hosts and even cooks for a dinner with Keith and Jules, constantly getting at their and Deb's nerves, and afterward warns her Keith won't forgive her if he tells him their dirty secret; Keith tells Lucas Jules just accepted his wedding proposal. After researching regulations, Brooke starts hard action- they are all fired, and threaten to tell the public about his inferior crab supplies, and get a raise, but quits anyhow and turns her attention to Felix and running for student council president. Karen gives up forcing Lucas- and hears he just took the test.

Brooke plans her presidential campaign with Felix; her opponent is confident, never-defeated Erica Marsh, who lives for the job. Dan asks Lucas to move in with him while offering Keith to pay for a grand wedding with Jules. Nathan discovers lovers e-mail to Chris from Haley on their computer, believes her most are from Taylor and they decide the stirring sister must leave. Jake is back for good, moves in with Peyton and asks coach for a good word at school. Erika plays the campaign dirty, so Brooke decides to pull all the stops and asks Lucas to write her a killer speech- he suggest a J.F. Kennedy address. At the club Tric, Chris Keller is back, as artist opening act; he also dares Nathan about Haleys love, and once the main act 'the Wreckers' has asked him along on their tour invites Haley to join them- she tells Nathan she wants to, solely as a unique career opportunity, and is told to choose: the tour or him, and yet she goes. Karen fails to stop Lucas moving to Dan or at least find out why: he will pay for Lucas' medication, as he was not tested negative but showed her Keiths results.

Lucas and Peyton hide Jake and Jenny at Nathan's place while he chases Haley. Lucas finds Dan's secret hiding place for cash and a secret ledger; when he and Andy come to get it at night, all is gone. Anna's former lover Darby turns up; she ends up coming clean to her parents, who still love her, but returns to boarding school. Nathan accepts an invitation to spend the night at the bar where Taylor works; they drink heavily and participate in the bar dancing show. Niki claims Jenny isn't Jake's biologically. Brooke stays late at a party without permission, misses her shift in the café, and learns to pay her debts and her dues chore-wise. Jake won't hear reason from his lawyer and chooses jail over handing over Jenny to irresponsible Niki, even if that's his best chance to get her back in a few months.

Nathan and Jamie join Haley on tour as it comes to a close. Quinn gets her divorce from David. Millicent appears in court for her DUI where Victoria offers her a job as her assistant at Clothes over Bros. Brooke finds it hard to trust Julian particularly when Alex is always by his side and ends up turning to new menswear designer Alexander Coin. Elsewhere, Haley and Quinn's sister Taylor turns up in Tree Hill with Quinn's ex-husband David who is now her boyfriend. Meanwhile, Mouth returns from L.A.

Nathan tries to calm Haley down after Taylor and David's shock announcement that they are a couple and then through the ensuing dinner that Taylor plans out until all three James sisters find themselves in the pool fighting it out. David and Quinn talk and he agrees with her that their marriage is at an end. Julian takes offense to the director hired for his new film and fires him after he punches him for insulting Alex. Finally after talking to Brooke rationally and asking her to be the movie's costume designer she makes him see that he should direct the movie himself which he brings up with his father who agrees. Mouth and Lauren fix up the disheveled apartment after Millicent's recent partying and then tells Millicent he is staying in Tree Hill. Millicent and Brooke agree to try and be friends again.

Haley, Quinn and Taylor receive a surprise visit from their mom Lydia who tells them that she has incurable pancreatic cancer and that she is not seeking any further treatment. Quinn takes the news very hard but Clay is there to support her. Meanwhile, Alex sets her sights on Alexander as Brooke and Julian try to get their old relationship back on track, and Millicent finds herself struggling with temptation.

In getting back at Julian for sleeping with Alex, Brooke messes with the costumes for the shoot and generally does her best to wound Julian but it takes comments from Alex to get her thrown off the set after she punches Alex in the face. Only later does she discover that it was Alexander that Alex slept with as she switched rooms with Julian. She tells Victoria who is furious and it later transpires that her mystery lover is Alexander. Meanwhile, Lydia takes ill from her cancer and is hospitalized and reaches out to the daughter Taylor but it is Quinn who manages to get her to come before she dies. Elsewhere, Clay tells Katie he won't be representing her but it doesn't put off Katie and she finds out that he was married to Sara so she transforms herself to look like her. Lauren and Mouth nearly get it together only for Skills to come back to Tree Hill.

The big day has finally arrived and the gang gathers at the hospital to await the birth of Haley and Nathan's baby. While they wait, they reminisce about the memories they have shared over the years.