It's four years into the future and the Tree Hill gang has finished college. Now, their lives have taken completely different directions. Lucas has written and published a book, Brooke has made it big in the fashion industry with her brand "Clothes Over Bro's", Peyton is pursuing a career in the music business, and Nathan and Haley continue to raise a now older James.

Now that Peyton and Brooke are back in Tree Hill, Lindsey worries that the two might threaten her and Lucas' relationship. Meanwhile, Nathan visits Dan in prison (his first visit in four years) and gives him a picture of his grandson. Meanwhile, Haley tries to persuade Quentin to return to school, Brooke opens her store in the old Karen's Cafe and Peyton signs her first band.

Peyton wants Haley to work with Jason on his music but he refuses to. Mouth is involved in a relationship with his boss and age is a factor in it. As the opening of Clothes over Bros approaches, Brooke finds herself in a few problems. Nathan takes strides to help Quentin.

In this flashback episode, memories are looked back upon. Lucas surprises Peyton in Los Angeles and they talk. He asks her something and is left with a surprising answer. Meanwhile, Nathan's temper triggers up after a guy reminds him of his cheating in high school basketball games.

It's confrontation time in Tree Hill, as Lucas confronts Peyton about her nasty behavior towards Lindsey and Brooke must confront Victoria about meddling with Peyton's record label. Meanwhile, Nathan begins to grow closer to Carrie, Haley continues to struggle in dealing with Quentin, and Mouth must choose sides between his co-workers and Alice.

The Honorary Title performs at Tric and Mia plays her song there as well. Carrie tries to get closer to Nathan. Brooke sets Mouth up on a blind date with her assistant and Lindsey confronts Lucas about Peyton.

On the eve of Lucas and Lindsey's wedding, they conspire to save Nathan and Haley's marriage. Brooke pairs Peyton with an old boyfriend, while Rachel and Dan return to Tree Hill.

In the sixth season premiere, Tree Hill residents must make a decision that will change their lives forever. Lucas finally pursues his dream with the woman he loves, Brooke must face a reunion with her mother, Mouth makes a revelation, Nathan and Haley must face a ghost from their past and the news of Dan's accident is slowly beginning to spread.

Brooke takes a trip to New York with Victoria. Peyton begins connecting with Mick Wolf, who begins telling stories about her parents. Haley continues having problems with a student and Nathan is confronted by a vision of Quentin.

The parents of Tree Hill face difficult challenges: Lucas finds himself fighting to stay calm when Peyton's pregnancy faces further problems, Nathan and Haley clash over the decision to pull Jamie out of school, and Victoria returns to tempt Brooke back into the business. Meanwhile, Mouth continues to mend his relationship with Millie.

Nathan and Haley both face their dreams as he questions his ambition to play in the NBA and she receives an offer from Nick Lachey. Meanwhile, Brooke learns something that could change Sam's life forever, Jamie attends his first school dance, and Lucas and Peyton take a road trip.

The families of Tree Hill draw closer as Lucas bonds with Jamie while working on Peyton's car, Sam develops a connection with Victoria, and Brooke and Haley throw Peyton a baby shower. Meanwhile, Nathan's ambitions seem closer than ever when he learns that an NBA scout will be watching his next game.

Lucas and Peyton's wedding day finally arrives, bringing some surprise guests along with it. Haley finds herself playing an unexpected role in the ceremony, as Skills and Brooke try to control Jamie and Nick. Meanwhile, Nathan continues to hope to be drafted into the NBA.

Tree Hill bids goodbye to the past while anticipating the future: Lucas and Peyton prepare for the birth of their child with the help of a surprise visitor, Dan nears his end, and Brooke works with Victoria to relaunch Clothes Over Bro's. Meanwhile, Nathan returns to Tree Hill to face Haley and Jamie after being released from the Chiefs.

Nathan’s scandal becomes public. Brooke’s fashion show brings an unexpected responsibility for Millicent, and Haley convinces Quinn to talk to her estranged husband David. Meanwhile, Mouth makes a decision that could threaten his career.

Nathan reaches the breaking point with Clay, causing a rift between Haley and Quinn. Brooke comes clean with Julian about her worries regarding his growing connection to Alex. Meanwhile, Skills pursues a new career in LA and Millicent’s drug problem worsens.

Nathan and Haley’s careers bring about a tough decision for the family, and Julian divulges a secret to Alex that leads to a confrontation with Brooke. Meanwhile, Clay tries to resuscitate his career as an agent, and Jamie learns the truth about Skills’ new job. And a fresh-from-jail Millie finds an unlikely supporter in Victoria.

As Nathan and Haley prepare for the family’s move to Barcelona, Brook struggles to accept Julian’s reaction to Alex’s crisis. Quinn helps Clay hatch a plan to win back Nathan as a client. Meanwhile, Millie’s downward spiral puts her and Mouth at a crossroads, and Dan Scott’s pronouncement shocks Rachel and his audience.

The Scott family joins Haley on the last leg of her tour, while Brook and Julian reconnect after their 6-week break. Clay and Quinn try to figure out how to move forward after his public declaration of love, and a post-rehab Alex tries to make amends with herself and the people she's let down.

Nathan tries to keep Haley calm after Taylor shows up at their house with Quinn’s ex-husband in tow. Julian sticks up for Alex on the set of their movie, and Brooke leans on Alexander to ease her heartache. Meanwhile, Clay gets a chance to prove his commitment to Quinn by helping her through a dinner with her sister and David.

Brooke and Julian try to find a balance between their personal lives and work as the movie shoot begins. Nathan and Haley receive a surprise visit, and Clay supports Quinn as she faces some unexpected news., Alex sets her sights on Alexander, and Millicent finds herself struggling with temptation.

Nathan tries to help Haley and Jamie confront Lydia's seemingly hopeless situation, while Brooke and Julian navigate their volatile relationship in the midst of a hectic movie shoot. Meanwhile, Clay and Quinn spend some time apart, and Miranda tries to prove to Grubbs that she's the right person to produce his album.

As Brooke angrily deals with Alexs tryst with Julian, Lydias condition worsens, prompting Quinn and Haley to try to reconnect with Taylor. Clay is forced to deal with Katies unsettling advances, and Nathan helps Jamie come to terms with Lydias impending death.

On the eve of Quinn’s big gallery opening, an uninvited guest ambushes Clay. Nathan spends the day with Jamie, while Haley struggles with life after her mother’s passing. Brooke and Julian each receive a shocking surprise. Meanwhile, Skills learns the truth about Lauren and Mouth.

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 Clay is confronted by an unhinged Katie.

Nathanstruggles to reach an increasingly despondent Haley, while Quinn leads Jamie on a Tree Hill treasure hunt. Julian shows his finished film to Brooke, and Clay is forced to deal with a deranged Katie.

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.

Brooke deals with the mounting financial problems at Clothes Over Bro's; Julian starts a new film project; Alex and Chase spend an afternoon together.

Nathan considers leaving the NBA; Victoria and Brooke try to handle the company's financial problems; Chase learns a secret about Alex.

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

Brooke and Julian’s wedding day is finally here. Dreams become reality, secrets are revealed and wedding hookups are inevitable.

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.

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.

As Brooke and Julian begin to adjust to life with their new children, Haley and Nathan find themselves dealing with similar issues. Although they don't know it yet, faces from the past threaten to interrupt plans for all their futures. Meanwhile, a mysterious problem arises for Clay and Quinn.

Brooke and her father discuss a new business venture; Julian worries about his investment; Quinn talks Clay into getting help; Millie tries to be honest with Mouth; Alex receives a tempting offer.

Dan helps a struggling Haley at Karen’s Café. Meanwhile, Quinn discovers that Clay is hiding something from her, and Chase tries to mend a broken heart. Brooke is let down by her lunch plans with her dad, and Julian makes a life-changing mistake.

As Haley prepares to emcee the annual Tree Hill Burning Boat Festival, Brooke uses the opportunity to process her father’s betrayal, while Julian tries to breathe new life into a past idea. Mouth and Millie make a change to their morning show, and Clay and Quinn get ready for Logan’s first night at the beach house.

In the final chapter of One Tree Hill, the tenth anniversary of Tric brings old faces and new possibilities for the Tree Hill family.