As Lucas begins to start casting for his movie, Peyton begins to put together plans for their wedding. Meanwhile, Dan gives Jamie advise when he has his first school crush; Brooke is introduced to the actress that will play her in Lucas' movie; Nathan receives exciting news; and Haley is forced to make a tough decision at work.

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.

A year has passed since Lucas and Peyton left Tree Hill, and the Tree Hill gang move forward after achieving their goals. Nathan has completed his first year in the NBA, Haley has taken over Red Bedroom Records, and Brooke continues to run Clothes Over Bro's while moving forward in her relationship with Julian.

While recording her new album, Haley must work to save Red Bedroom Records and enlists Mia's help to do so. Meanwhile, Brooke, with Millicent's help, searches for the new face of her clothing line; Clay defends Nathan as the scandal continues to grow; Julian and Brooke decide to move in together; and Dan returns to Tree Hill with a new bride in tow.

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.

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.

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.

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

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.

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.

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.

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.