Nathan and Haley must parent Jamie in the face of a school bully, while Lucas and Peyton adjust to life as a live-in couple. Brooke finds being a role model not as easy as she expected, and Marvin gets his old job back. Marvin is surprised to find out that his new intern is someone from his past.

Jamie and Haley really worry that Nathan might being injured at Slam Ball, although he scores well and Owen protects him even against the most feared adversaries. Brooke is so stressed out by Sam's misbehavior that Owen's efforts to win her back, exposing himself only to get overexposed cruelly, seem wasted. Lucas agonizes over whether and how to write the key script scene Julian demands, Keith's death. Peyton puts off telling him about her LA affair too long.

As Lucas takes a trip to Hollywood to meet his film director, Nathan gets a pro basketball try-out. Peyton struggles with Mia to focus on her follow-up album, while Millicent confronts Marvin about Gigi. Julian approaches a dubious Brooke about designing clothes for his movie, and Haley takes a reluctant Jamie to his school talent show.

Julian's dad is fired as studio boss, his projects therefore in doubt. Director Reese Dixon worries about saving pay and perks, masterly. Dan's heart finally arrives, but is lost in a doggish accident. Jamie demands the truth about Keith, but stays loyal. Sam sees Jack commit shoplifting and takes both loot and blame. Julian learns the truth and must decide whether to leave Tree Hill and Brooke. Haley may return as teacher if she publicly withdraws her support for Sam's article. She leaves to join Peyton's label as Mia's producer.

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.

The tree hill gang must learn that to live an exceptional life doesn't end once you've achieved your goals. With Lucas and Peyton gone, Nathan's a year into his NBA career, Haley has taken over Red Bedroom Records, and has to deal with the return of her free-spirited 26 year-old sister, Quinn. Brooke is still happy with Julian.

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.

Nathan, Julian, Mouth, Skills, James and Chuck go camping. Back in Tree Hill, Haley, Brooke and Quinn enjoy some "special" brownies. Meanwhile, Clayton continues to deal with his mourning issues and Dan has nightmares about a dying boy.

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.

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.

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.

As Halloween approaches in Tree Hill, Brooke and Julian get an unexpected visitor, and Nathan begins a new career. Meanwhile, Clay and Quinn struggle with life back at the beach house, and Haley and Mia host an open mic night at Tric.

A storm strikes Tree Hill, putting everyone's life in danger.

Brooke, Quinn and Haley decide to use their talents for the greater good. Meanwhile, Julian takes on a directing job and helps out a friend, and Chase mentors Chuck.

Sex games, secrets and shoelaces all come into play as the couples of Tree Hill celebrate Valentine's Day.

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.

As Haley's due date approaches, she takes steps to ensure that all her friends and family will be ready when the time comes. Brooke and Julian also prepare to begin a family, while Chuck turns to Chase for help with a problem.

As Nathan, Julian and Clay coach Jamie's first little league game, the situation regarding the accident comes to a head. Meanwhile, Chase asks Alex to take a drug test for him, and Quinn gets an offer to shoot in Puerto Rico.

Nathan, Jamie, Clay, Julian, Chase and Chuck have a camp-out on the Rivercourt. Meanwhile, Brooke, Quinn, Alex and Lauren take a trip to Puerto Rico.

Haley and Brooke get ready to re-open Karen's Café as Brooke's pregnancy progresses. At her scan she discovers that she is expecting twins. Nathan and Clay set off on the road to scout new talent and it forces Nathan to finally go and see Dan. Chase leaves for the Air Force leaving behind two disappointed people - Chuck and Alex. Meanwhile, Mouth and Millie start their new morning show together but Millie is wooed away to start a new show with another co-anchor in Charlotte.

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.

Chase bravely bares Chuck's absurd, imitative adoration for 'cool', actually neglectful Chris Keller and stands by the ingrate knave when his father Wade Scolnic finally visits, but discards Chase as if a random babysitter. Nathan is missing since his flight home from Europe days ago. After cocky Keller helps activating Tree Hill PD officer Stevens, Haley finds Dan's cash stash and suspects a horrible crime. Julian can't forgive himself even now his loved-ones do, blames himself for bullying by strangers and picks a bar-brawl to get a 'bloody good' beating. Pushed by Dan and Quinn, Clay checks in for residential therapy with Dr. Alvarez, keeps dismissing 'mere talk' as therapy, but decides against signing out after meeting shy Logan, a neglected orphan boy who hangs around the rehab clinic.

Haley seeks help from Lucas as Nathan makes an escape attempt. Brooke comes face-to-face with Xavier. Julian uncovers evidence that assists Dan in his search for Nathan. Clay makes a connection with another patient.

Haley receives news of a possible tragedy. Dan's search for Nathan leads him back to his dark past. Clay has a breakthrough in his treatment. Brooke and Julian deal with Xavier. Chase's concern for Chuck pushes him to his limits.

Brooke and Julian take new measures to protect their family. Skills helps Mouth get to a turning point, and Chase faces consequences for defending Chuck. Clay reaches a new understanding with Logan.

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.

Sex games, secrets and shoelaces all come into play as the couples of Tree Hill celebrate Valentine's Day.

Brooke and Julian take new measures to protect their family. Skills helps Mouth get to a turning point, and Chase faces consequences for defending Chuck. Clay reaches a new understanding with Logan.

Nathan and Haley must parent Jamie in the face of a school bully, while Lucas and Peyton adjust to life as a live-in couple. Brooke finds being a role model not as easy as she expected, and Marvin gets his old job back. Marvin is surprised to find out that his new intern is someone from his past.

Brooke, Quinn and Haley decide to use their talents for the greater good. Meanwhile, Julian takes on a directing job and helps out a friend, and Chase mentors Chuck.

Haley receives news of a possible tragedy. Dan's search for Nathan leads him back to his dark past. Clay has a breakthrough in his treatment. Brooke and Julian deal with Xavier. Chase's concern for Chuck pushes him to his limits.

Haley seeks help from Lucas as Nathan makes an escape attempt. Brooke comes face-to-face with Xavier. Julian uncovers evidence that assists Dan in his search for Nathan. Clay makes a connection with another patient.

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.

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.