On the eve of their wedding, Nathan worries for Haley's safety while Peyton and Brooke's friendship is tested. Deb tells Dan the truth about the dealership fire, and Karen finds herself needing Keith more than ever.

On the night of the rehearsal dinner, Brooke tangles with Haley over Haley's wedding dress. Lucas and Karen return to Tree Hill and Peyton makes a startling discovery.

It's the weekend of the Coastal Classic, and with Lucas sidelined, Nathan has to step up on the court against an old rival who shows an interest in Haley. Brooke and Mouth plot revenge against Rachel while Dan goes head to head with Nathan's Uncle Cooper. Also, Peyton makes a life-altering decision.

Lucas struggles with the decision of whether he should play basketball in the wake of Keith's death. Brooke forces Rachel to deal with a dark secret. Nathan and Haley's wedding reprise is put to the test and Peyton decides to visit Pete in Chicago.

Rachel invites the gang to her family's cabin for a weekend getaway. Lucas, Brooke and Nathan conspire to surprise Haley while Peyton receives an unexpected visitor at the cabin. Mouth harbors resentment towards Rachel, and a game of "I Never" reveals a secret. Meanwhile, Karen confronts Dan about Keith's death.

The aftermath of the school shooting and the death of Jimmy Edwards forces everyone in Tree Hill to examine their lives. Nathan reassesses his relationship with Haley, while Brooke and Rachel join forces to heal the student body. Dan must deal with the ramifications of shooting Keith, while Lucas and Peyton consider the implications of their kiss in the library.

A normal day becomes deadly when a despondent student brings a gun to Tree Hill High. While lives hang in the balance, Nathan and Lucas put themselves at risk to protect their friends and loved ones.

When someone unleashes the students' time capsule upon Tree Hill High, Lucas and Mouth must confront a person from their past. Brooke has to deal with the revelation that secrets aren't the only things she exposed in the time capsule. Dan learns to forgive Keith. Haley is forced to reconcile the man Nathan was before with the man he has become, and Peyton's Breast Cancer Benefit Concert at Tric features performances by Haley, Jack's Mannequin and the return of Fall Out Boy.

Brooke is forced to grow up in a hurry when her trip to a New York City fashion show prevents her from attending an annual cheerleading tournament. Nathan and Lucas are influenced by the father of an old friend. Struggling with her mother's cancer, Peyton joins Rachel for a night of blowing off steam, and Haley and Nathan use their hotel room as the honeymoon suite they never had.

A violent rainstorm knocks out the power in Tree Hill, leading Haley to Nathan's doorstep and Brooke out into the downpour for a dramatic confrontation with Lucas. Peyton finally confronts the truth about Ellie's illness, while Mouth is tempted by his new friend, Rachel. Before morning, secrets are revealed, relationships are tested, and new love gets hotter than ever.

When a guidance counselor challenges the students of Tree Hill to consider their futures, Nathan and Lucas feel pressured to impress an important basketball scout. Mouth gets caught between Brooke and Rachel, Peyton and Ellie grow closer while finalizing their CD, and Dan tells Haley Nathan paid Chris Keller to come back into her life.

After losing their second game of the season, the Ravens receive tough love from Whitey. Peyton and Ellie try to recruit rock band Nada Surf for their benefit album. Haley reveals a disturbing fact to Nathan, and Brooke plans a romantic night for Lucas after learning that he submitted her fashion designs to a prestigious competition in New York.

Lucas and Peyton take a road trip together to find Ellie. While out of town, Lucas reconnects with a friend from his past. Brooke, Haley and Mouth successfully launch the Clothes Over Bro's website, only to find that demand far exceeds supply. Deb reveals to Nathan that she tried to kill Dan.

Lucas reveals that he knows who tried to kill Dan. Brooke, Peyton and Haley find themselves behind bars. Chris Keller convinces Nathan to be his wingman at a high-stakes poker game. The residents of Tree Hill finally choose a mayor.

As the town readies for the Ravens' first basketball game, Lucas worries that his head and heart aren't in it. Nathan accuses Lucas of being the Ravens' weak link. Peyton and Haley mend fences to support Brooke in a time of need. When the mayoral race tightens, Dan resorts to a smear campaign.

As the fantasy draft dates begin, Brooke finds herself on an unusual double date, while Lucas gets closer to Rachel. Mouth spends time with an old friend and Peyton regrets choices she makes with Ellie. Karen and Deb take their campaigning to new heights.

In an effort to keep her cheerleaders from fighting over the same guys, Brooke devises a "Fantasy Boy Draft." Haley and Peyton butt heads over Nathan, while Lucas has trouble keeping up with the brutal pace of basketball practice. Meanwhile, as the election nears, mayoral candidate Dan clashes with his new opponent.

It's Midnight Madness in Tree Hill as the Ravens officially begin basketball practice -- with explosive results. New hoops captain Nathan clashes with Lucas over Haley. Brooke fills a vacancy on the cheerleading squad, only to regret her decision when the new girl, Rachel, sets her sights on Lucas. Meanwhile, Dan's bid for mayor takes a surprising turn when an unlikely opponent steps forward.

It's party time in Tree Hill. A masquerade ball at Tric provides the perfect opportunity for Haley to win back Nathan's heart, and for Brooke to seduce Lucas. Punk-pop sensation "Fall Out Boy" performs amidst the costume madness, while Peyton tries to come to terms with the new mother in her life. Meanwhile, Dan gives Deb an ultimatum, but soon finds she's a much more worthy opponent than he thought.

It's the first day of senior year and estranged spouses Nathan and Haley have trouble adjusting as classmates. While Brooke continues to play hard-to-get, Lucas learns a troubling secret about Peyton's mom. Meanwhile, Dan closes in on the truth about the dealership fire.

Brooke organizes an "End of Summer Beach Party," but soon finds she's the only one in a party mood. Nathan comes home from High Flyers to reconnect with Haley, but he and Lucas are at each other's throats. Meanwhile, Lucas struggles with Brooke's new rules for dating, Peyton tries to come to terms with the new truths about her family, and Dan remembers what happened the night of the fire at his dealership.

Lucas awaits Brooke's return to Tree Hill after a summer spent with Peyton. Peyton investigates the mysterious woman who claims to be her mother while Nathan must deal with Haley's reappearance at the same time as the fire at Scott Motors. Dan's fate after the fire is revealed.