As promised, Lucas, Brooke, Nathan, Haley, Peyton and their Tree Hill gang meet up after 4 years of being apart. Haley and Nathan still live in Tree Hill with their now 4 year-old son, James Lucas Scott. Nathan's dreams of being a NBA star were smashed. Peyton has just quit her job in the record industry. Brooke is living in New York. Her multi-million dollar clothing line, Clothes Over Bros, has given her a successful career in fashion design. Lucas comes back Tree Hill with his new girlfriend, Lindsay, suffering writer's block. The group rekindles to see how much their lives have changed since the simple years of high school

Haley tries to encourage a student, who is a troublemaker, to join the Ravens. Nathan goes and vists Dan in prison, without Lucas aware. Brooke is edgy after her manager, tracks her down in Tree Hill. Peyton finds new talent for the reopening of Tric, with the help of Haley. Lucas lets Peyton be the manager of Tric. Linsday, Lucas's girlfriend is worried after meeting Brooke and Peyton.

Brooke buys Karens Cafe, and turns it into a Clothes Over Bro's boutique. Everyone goes to the opening of the store, including Brooke's Manager mother, who has seemed to track her down. Lucas and Peyton cause friction at the opening.

In a flashback of three years into the past, an event between Lucas and Peyton changes their relationship forever. Brooke has to decide about the fate of her fashion line since Victoria is putting pressure on her. Whitey has doubts about Nathan as he has a sudden temper problem before a championship game because of Haley who is trying to find the balance between her school and motherhood.

Nurse Carrie isn't just an ideal playmate for Jamie, who has nightmares since Skillz told him too much about Dan. Her charms should make Haley jealous, but she doesn't realize yet that Carrie really lusts for the hunky husband. Mouth is deputized by the night-shift to ask for better working conditions from their boss Alice; he actually may earn a TV reporter spot as her "play thing". Peyton clashes instantly with Brooke's bossy mother, Victoria, who scares her new label's only star, Mia, and calls Brooke too dumb to run the fashion business herself. Lucas considers proposing to Lindsay and won't accept Peyton's claim that he 'gave up on their true love' during or after his 'ambush proposal'.

It's a Tree Hill reunion as the entire gang gathers at Tric to see musical group The Honorary Title perform. Victoria turns up at the club which infuriates Brooke. Meanwhile, Brooke sets up her assistant Millicent with Mouth but Alice ruins the set-up for him by threatening to have him fired if he kisses Millicent. Peyton arranges for Mia to sing at Tric and Lucas proposes to Lindsay which stuns Peyton.

Missing Nathan gives Jamie nightmares about Dan, who is indeed paroled. Lucas and Lindsay decide to 'coincidentally' have separate stag and hen nights at the same place, so Nathan and Haley are bound to meet. Brooke arranges a hot blind date for Peyton, but the joke is on her as Owen's chosen mate is Chase, Brooke's former 'clean teen' lover. Jamie's tireless efforts to get his mom and dad to make up In turn make Haley realize she shouldn't have tried to change Nathan. Ruthless business adviser and absent mother Victoria pushes Rachel out, to Brooke's disgust.

The girl of Lucas' dreams shows up at the airport. Nathan's comeback is halted by news that could change his career, while Dan's life hangs in the balance. Marvin and Millicent wrestle with leaving Tree Hill, as Brooke and Victoria's battle over Clothes Over Bros comes to a surprising head.

Knowing about his mother's affair with Skills, Nathan tells her to leave, but finds Jamie and his granny miss each-other. Of all people she happens to tell crazy Carrie. Jamie's insistence to visit grandpa Dan brings Haley to discover his disappearance and investigates. Brooke seeks counseling now that her mother has stolen her fashion company, then goes to confront her, armed. The shoplifter is in Haley's class. Peyton is delighted to work and spend time with singer Mick Wolf, who also knew her late mother and biological father.

Nathan and Haley are considering a better school for genius Jamie, but doubt that academic excellence outweighs posh elitism and absence of sports. Nathan is expected to step up as leader - by coaching his ingrate rival Nino. Peyton has a car accident, which wrecks Lucas' Comet on wheels. Sam's boyfriend has found cool foster parents, and must leave Victoria expects Brooke to help save the company she stole, if not out of family loyalty then for the employees.

Nathan is offered a two year pro contract, but in Europe. He agonizes whether he should take it, as Bobby suggests, or stick to his NBA dream, as Haley advices. Jamie not only does well at his first school dance, he is the one who counsels 'babsitter' Skills to date his teacher there. While Peyton grumbles bedridden, Lucas repairs the Comet as a surprise, while both reminisce. Chase must convince Mia his affair with Brooke was and could only happen before them. Haley enjoys working with Nick Lackey, who wants her to produce music.

Warned by manager Bobby there's an NBA scout, Nathan and his protégé Nino perform excellently, then wait for a call. Lucas opposes Peyton preparing a 'posthumous' time-capsule and ask for a rushed marriage on account of her pregnancy risk. Nathan makes him reconsider and drops off Jamie with 'his uncle Keith'. Brook, Sam and Victoria are too busy to concentrate on Peyton's baby-shower or business. They are preoccupied as to whether Sam should be encouraged to spend time with birth mother Rebecca.

Peyton and Lucas' wedding day has finally arrived and surprise guests attend. Haley plays an unexpected role in the ceremony while Nathan hopes to be called up to the NBA. Antwon keeps Jamie on a short leash, and Brooke does the same with Nick Lachey.

Nathan gets some news about his future on the Chiefs. Peyton gives birth to hers and Lucas' baby daughter, Sawyer, and receive a surprise visit from Karen. Dan is on death's door, while Brooke and Victoria prepare to re-launch Clothes Over Bros.

A disgruntled Renee makes her pregnancy known in the national media. Quinn tells David that she wants a divorce and spends the night with Clay. Mouth quits his job at the station after he is forced to report on the scandal surrounding Nathan. Brooke's fashion show is a huge success but Victoria warns her about Alex and Alex's obvious designs on Julian.

After losing his place on the Charlotte Bobcats Nathan reaches breaking point with Clay and fires him but this ends up causing a rift between Haley and Quinn with Quinn moving out to a hotel. Dan takes it badly that Clay messed up and tries to teach him a lesson by nearly drowning him in the surf. Later Clay is fired by his boss for stuffing up Nathan's contract. Victoria arrives unannounced and takes a liking to new TRIC bar manager Grubbs. Meanwhile, Brooke tells Julian that it is doubtful that she will ever be able to get pregnant and he promises to get different opinions and they will work it out. Elsewhere, Millicent's increased drug taking alarms Mouth and her model like tendencies and demands disgust Brooke. It prompts Victoria to call the police when she sees Millicent driving drunk. Millicent calls Brooke from jail but Brooke tells her she cannot help her.

Victoria bails Millicent out of jail the morning after her arrest and tells her to get herself together before she shows herself again. But Victoria is doubtful that Millicent has learned her lesson and proceeds to keep an eye on her and she is proved correct when Millicent steals a dress from Brooke's new collection to give to her model friend Makenna is exchange for a packet of blow. Mouth is distraught at the change in Millicent and they break up. Clay tries in vain to hold onto his one client but it is not to be and so he packs up his apartment much to Quinn's dismay. Nathan is told by his agents that he won't play NBA this season and his only option is to play in Spain and be ready for the next season but this move coincides with Haley's planned record tour of the US. Skills records a video with the help of Jamie for a new job in L.A. Elsewhere, Julian mistakenly tells Alex that Brooke cannot have children which further deepens the rift between Brooke and Julian after Alex tries in her own way to help Brooke. Despondent after being told to stay away from Julian Alex slits her wrists in the bath and leaves Julian a voice-mail telling him she won't bother him anymore.

Clay gets his mojo back with some help from Quinn and which might mean that Nathan can stay in the US and play in the NBA with the his old team the Charlotte Bobcats instead of going to Spain. Skills gets offered and takes the job in Los Angeles and brings Mouth along for the ride. Dan goes against Rachel on his television show and tells his audience that this is his last show and also serves with divorce papers. Julian rescues Alex from her near suicide bid and tells her the film deal is back on. Brooke fires Millicent from her model contract and tells her to get immediate help for her drug problem but her stay in rehab is brief. Victoria hires a new designer, Alexander Coin, for the menswear collection without telling Brooke.

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.

Haley and Quinn refuse to accept that their mom Lydia will not fight her pancreatic cancer and after some convincing manages to persuade her mother to get a second opinion with Nathan's doctor but the results don't bring any change. Because she told Jamie that she won't be alive for Christmas he organizes for her to have Christmas now with the family. Meanwhile, Brooke and Julian's relationship moves up a notch but comes crashing down spectacularly when Brooke finds Alex in his bed but is it what it seems? Elsewhere, Grubbs puts Miranda through hoops before he allows her to produce his album with her and Owen Morello comes back into Millie's life much to Mouth's displeasure.

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.

Quinn's gallery opens with Clay very supportive unaware that he is being stalked by Sara lookalike Katie until she makes her presence known and Clay shows Quinn how alike Katie is to Sara. Josh's sex tape with Alex is emailed to Julian's father with a demand for $1,000,000 putting the film in jeopardy. Miranda finds out she is being deported thus putting a spanner in the works with Grubbs's recording but Grubbs finds a way around it by proposing to her. Lauren tells Skills that she has fallen for someone else but he is unaware it is his best friend Mouth until he sees a photo of them at the gallery where he promptly punches Mouth. Meanwhile, Victoria's affair with Alexander is exposed in more than one way. Elsewhere, Nathan and Jamie spend a guys evening together & later he asks Haley if she'd be ready to try for another baby. She tells him she took a pregnancy test and it was negative but is she telling him the whole story?

Nathan and Haley struggle with the aftermath of her mother's death, while Brooke deals with the fallout of Alexander's tryst with Victoria. Alex discovers a secret about her leading man, Josh, that could derail Julian's film, and Quinn is confronted by an unhinged Katie.

Quinn takes Jamie on a treasure hunt as an increasingly despondent Haley further withdraws from both Nathan and Jamie. Katie invades Clay's personal space convinced that she is his dead wife Sara. Clay plays along until he manages to have her committed. Mia breaks up with Chase by text and then comes back to Tree Hill to manage a heart-broken Grubbs after Miranda leaves. Julian shows his film to a delighted Brooke as he anxiously awaits confirmation on whether his indie film will be bought by a film festival.

As the gang returns from Utah, Brooke and Julian are engaged, Haley learns that she is pregnant, Nathan must leave for training camp, and Clay and Quinn are assaulted and shot by Katie.

Clay and Quinn discover they've been shot, and as they fight to live, Nathan and Haley struggle with the situation. Meanwhile, Julian tries to preoccupy Jamie, and Brooke's legal troubles mount.

As the situation at the hospital worsens; Nathan makes a huge decision regarding his career. Brooke and Julian take Jamie for the day, while Victoria and Millicent hatch a plan.

As Brooke deals with the mounting financial troubles at Clothes Over Bro's, Nathan and Haley come to a conclusion regarding Nathan's career. Meanwhile, Julian begins a new film project, while Alex and Chase spend the afternoon together.

As Clay is discharged from the hospital, Nathan contemplates walking away from the NBA. Meanwhile, Brooke and Victoria disagree on how to handle the company's financial problems, and Chase discovers a secret about Alex.

The gang gathers at Nathan and Haley's to spend Thanksgiving with friends and family.

The biggest day of Brooke Davis' life has arrived, her wedding day. Julian gets his parents to agree to a truce on their special day, but will they uphold their end? Brooke makes up with her mom, and when her dad fails to turn up, her mom walks her down the aisle. Nathan's advice of sincerity helps inspire Julian's 'best man' Jamie to make a brilliantly simple speech. Chase disagrees with Skills' absurd security-obsessed job description for them as ushers. He ends up making hotter use of the limousine.

As the girls plan a surprise baby shower for Haley, the guys participate in try-outs for Jamie's baseball team. Meanwhile, Brooke and Julian pursue adoption, while Mouth gets Millicent ready for her first day at work.

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.

While Haley stays at home to take care of the new baby, Quinn organizes a concert at Tric. Meanwhile, Brooke gets an offer to return to Clothes Over Bros, and Nathan sets his sights on exposing Professor Kellerman.

Before tired Nathan can finally rejoin his longing family, Dan has turned up and secured himself a temporary stay on account of his burnt-down restaurant, where he lived, but may have torched it. Chase is happy but exhausted on account of running the bar and an intense sex life with Alex. As if nocturnal baby care exhaustion wasn't bad enough for Julian and Brooke, his studio project only seems to bring debt and her boys fashion label fails to get financed, but her father Ted Davis actually turns up for the twins' christening. Clay's exhaustion is diagnosed medically serious. Chris Keller got engaged by Haley's music label under an alias, immediately antagonizes Alex but proves himself an genius producer.

Chase confides only in Chuck his plan to move Alex's things into his place. They ignore Chris Keller made her an offer for a career-boosting, national tour. As even the psychiatrist Clayton grudgingly consults can't properly diagnose his problems, Nathan decides with support from Jamie and Haley to attend in his pace the European forum for international sports talent scouting. This allows Dan to prolong his stay and carry out a mysterious plan. Julian warns Brooke that Victoria tries trough him to sabotage her father's apparently business-wise sound project to co-found a male fashion label.

Chase is heartbroken after Alex's desertion to take the tour Chris Keller advised, yet overcomes his bitterness toward Keller, who pleads her artist temperament was a lost case from the start. Julian is near despair about the unused studio until a TV series project comes within reach. Alas coaxing the studio proves tragically incompatible with paternal duties, while Brooke charms investors for her boys fashion project with her father. Clayton's problem is worse then thought, as Quinn discovers spying on him. Haley now runs Karen's café, but her cook is sick, so Dan steps in but that costs some bigot customers, and a mystery competitor opens across the street.

Julian finally sells his One Tree Hill series concept to a studio and is hired to complete the script. Clayton and Quinn, who welcomes Sara's memory to, patiently win Logan's trust to become a warm; close family. Chase gets over his confidence crisis as bar manager just before he's offered a chance to buy Tric from Karen on the boat burning day. After Julian scolds father-in-law a useless father and Brooke 'surprises' her divorced parents back in bed, an unexpected business move makes up for a lot.

In the final chapter of One Tree Hill, the tenth anniversary of Tric brings old faces and new possibilities for the Tree Hill family. To celebrate the 10th anniversary they host a concert at Tric that includes Gavin Degraw. Julian buys Brooke's childhood home for them to live in. Nathan and Haley celebrate their 10th wedding anniversary.

Quinn takes Jamie on a treasure hunt as an increasingly despondent Haley further withdraws from both Nathan and Jamie. Katie invades Clay's personal space convinced that she is his dead wife Sara. Clay plays along until he manages to have her committed. Mia breaks up with Chase by text and then comes back to Tree Hill to manage a heart-broken Grubbs after Miranda leaves. Julian shows his film to a delighted Brooke as he anxiously awaits confirmation on whether his indie film will be bought by a film festival.

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.

Chase confides only in Chuck his plan to move Alex's things into his place. They ignore Chris Keller made her an offer for a career-boosting, national tour. As even the psychiatrist Clayton grudgingly consults can't properly diagnose his problems, Nathan decides with support from Jamie and Haley to attend in his pace the European forum for international sports talent scouting. This allows Dan to prolong his stay and carry out a mysterious plan. Julian warns Brooke that Victoria tries trough him to sabotage her father's apparently business-wise sound project to co-found a male fashion label.

After losing his place on the Charlotte Bobcats Nathan reaches breaking point with Clay and fires him but this ends up causing a rift between Haley and Quinn with Quinn moving out to a hotel. Dan takes it badly that Clay messed up and tries to teach him a lesson by nearly drowning him in the surf. Later Clay is fired by his boss for stuffing up Nathan's contract. Victoria arrives unannounced and takes a liking to new TRIC bar manager Grubbs. Meanwhile, Brooke tells Julian that it is doubtful that she will ever be able to get pregnant and he promises to get different opinions and they will work it out. Elsewhere, Millicent's increased drug taking alarms Mouth and her model like tendencies and demands disgust Brooke. It prompts Victoria to call the police when she sees Millicent driving drunk. Millicent calls Brooke from jail but Brooke tells her she cannot help her.

As the situation at the hospital worsens; Nathan makes a huge decision regarding his career. Brooke and Julian take Jamie for the day, while Victoria and Millicent hatch a plan.

Nathan gets some news about his future on the Chiefs. Peyton gives birth to hers and Lucas' baby daughter, Sawyer, and receive a surprise visit from Karen. Dan is on death's door, while Brooke and Victoria prepare to re-launch Clothes Over Bros.

As Brooke deals with the mounting financial troubles at Clothes Over Bro's, Nathan and Haley come to a conclusion regarding Nathan's career. Meanwhile, Julian begins a new film project, while Alex and Chase spend the afternoon together.