When tragedy strikes in Tree Hill, Nathan and Haley experience difficulties breaking the news. Brooke still hurt over the robbery, questions her friendship with Peyton, and Lucas and Skills finally meet Quentin's mother.

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.

Peyton shares some startling news with Lucas, who discovers that Julian has been keeping another secret about the movie. While searching for runaway Sam, Brooke is forced to confront her lingering feelings over her attack. Nathan struggles with his new professional environment.

News of Peyton's condition spreads like wildfire through Tree Hill. Brooke tries to suss out Julian's intentions. Mouth and Millicent strive to keep their relationship going. Meanwhile, Brooke and Lucas babysit Jamie and his friend when Nathan and Haley spend a night out together.

As Lucas and Julian face a setback in their film production, Peyton and Haley team up to help Mia with her new single. Meanwhile, Brooke faces a crisis when Sam is arrested; and Jamie learns the truth about Dan and Keith.

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.

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.

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.