After four years, Tree Hill is a new place. Lucas is a struggling writer who is about to embark on a new coaching career with Skills. Peyton is at the beginning of a budding music venture, while Brooke's fashion line is at a crossroads. Meanwhile, Nathan and Haley are young parents trying to find their way.
Tensions run high as Lucas must face his past and choose his future, while he discovers the demands of being the coach of the Tree Hill Ravens. Haley's decision to hire a nanny brings much-needed help into their home, while her first day of teaching turns out differently from what she expects.
Lucas' editor wonders about the timing of his recent creative inspiration. Brooke and Peyton make business plans, while Mouth tries to win points with his boss Alice. Lucas and Skills finally make some headway with the Ravens, while Nathan tries to wrestle free from Dan's legacy.
As Brooke makes plans for Clothes Over Bro's, Peyton has her hands full when the musician she just signed turns out to be problematic. Haley's interest in music leads her back to the recording studio. Nathan's efforts to corral defiant player Quentin are unsuccessful. Meanwhile, Mouth's relationship with his boss grows heated.
Three years ago, Lucas visits Peyton in Los Angeles with an offer that will change their relationship forever. Under pressure from Victoria, Brooke must make a difficult decision about the future of her clothing line. Whitey is concerned when Nathan's temper flares on the night of the college basketball championship. Haley struggles to balance the pressures of school and being a new mom.
Peyton talks nasty to a bar owner, Owen, and later tries to apologize by seducing him. Meanwhile, Lindsey visits Lucas for the weekend and Nathan and Skills have an insightful conversation which leads to Nathan realizing that he is still not ready to talk about Dan.
It's a Tree Hill reunion as the entire gang gathers at Tric to see The Honorary Title perform. While Peyton and Haley see this as an opportunity to introduce their musical act, Carrie sees it as a chance to get closer to Nathan. Brooke forces an unsuspecting Mouth to go on a blind date with Millicent. Lindsey confronts Lucas about sneaking off to see Peyton.
Peyton admits her true feelings to Lucas. Brooke makes a play for Owen and Mouth tries to convince Millicent he's a better man than she thinks he is. Haley wrestles with whether or not to reveal information that could ruin Lucas' relationship, and Nathan is put in a position that could spell the end of his marriage. Lucas and Skills face the coaching prospect of playing their season opener at a disadvantage.
At the first Raven's basketball game of the season, Haley, Brooke, Peyton, Lindsey and Mia find themselves locked in the Tree Hill High library. Tensions run high as Peyton and Lindsey face off over Lucas.
When Brooke takes Owen to New York for a glimpse of her other life, she's faced with a ghost from her past. Haley reels from a devastating blow to her marriage, while Nathan and Lucas muster their courage to attend Dan's parole hearing. A major record label takes an interest in Peyton's recording artist.
On the eve of Lucas and Lindsey's marriage, they conspire to save Nathan and Haley's. Brooke pairs Peyton with a surprise old boyfriend, while dealing with Victoria. Rachel returns to Tree Hill to face old challenges, while Dan also returns hoping for a fresh start.
The wedding of Lucas and Lindsey doessn't go as planned, while two friendly faces return to Tree Hill for the 100th episode of the series.
Lucas picks up the pieces after being left at the altar by Lindsey, while Nathan and Haley deal with the repercussions of Jamie's abduction. Brooke is haunted by her past as she considers adopting, while Peyton gets a visit from an old friend.
Lucas and Peyton discuss Lucas' aborted wedding, while Brooke gets a phone call that could change her life, and Millicent and Mouth take a new step in their relationship. Haley takes the first tentative steps towards a new career, and Nathan contemplates what it would take to get his game back.
Lindsey returns to Tree Hill for Jamie's fifth birthday party, giving Lucas hope for their relationship. Brooke and Peyton prepare for life with a new baby. Meanwhile, Dan tries to insinuate himself back into the lives of his family, ultimately divulging a grave secret to Nathan and Haley.
Lucas investigates Dan's heart condition while Haley struggles with letting Dan into Jamie's life. Nathan urges Quentin to reinvent his game and Brooke juggles her career with life as a new mother. Peyton tries to assuage her guilt over Lucas' breakup, and Mouth gets a shot to be sports anchor.
Lucas is crushed by devastating news, while Brooke's baby undergoes emergency surgery. Haley wrestles with her decision to record a new album. Skills and Nathan employ a risky game plan to salvage the Raven's season and Lucas stuns Peyton with a shocking truth.
Brooke deals with giving up her baby, while Lucas deals with the residue of his actions following his game night scuffle. Haley has a musical breakthrough and Peyton gets news about a ghost from her past. Nathan and Jamie face their fears together.