Dan must face the harsh consequences of his decision to murder Keith as Karen and Haley's pregnancies complicate the lives of Nathan and the graduating seniors of Tree Hill High. Lucas wrestles with his post-high school options, and Peyton and Brooke prepare to spend the summer in Los Angeles together.

As graduation approaches, Haley prepares for the recital of her valedictorian speech and motherhood, Nathan must adjust to life without basketball, Brooke makes a confession that may have great consequences, and Lucas confronts Dan after Karen's life is threatened.

Brooke and Peyton finally rekindle their friendship, Nathan's past mistakes continue to haunt him and Haley, and Lucas hears a shocking confession from the witness to Keith's murder.

As the end of the school year approaches, Peyton considers participating in a music internship in Los Angeles, while Brooke tries to reconnect with Chase through yearbook signatures, and Haley struggles to write her valedictorian speech. Meanwhile, Dan suggests that Lucas get professional help when Karen worries about his obsession ...

It's Prom night, but things start to go awry as Lucas discovers who was the person in the hallway when Keith was killed, and Psycho Derek holds Peyton hostage at her own house. Meanwhile, Haley and Nathan vow to be romantic with each other throughout the night, and Dan continues ...

When Mouth and Rachel's road trip goes wrong, the other teens go out to their rescue. While on the trip, Nathan and Haley get a second chance to enjoy their Prom and Peyton and Lucas decide to take their relationship to the next level. Finally, Brooke reveals the truth about ...

It's Prom day, and emotions are flying high at Tree Hill. An emotional Haley confronts Nathan about the sex tape and asks for a list of all his past sexual encounters. Meanwhile, an angry Peyton asks Lucas to skip the dance altogether, but he refuses to take no for an ...

Haley confronts Brooke regarding the stolen calculus test. Lucas and Peyton consider taking their relationship to the next level as Peyton and Brooke grow closer. In Deb's absence, Nathan throws a senior party at the Scott House where a sex tape from Nathan's past surfaces.

Haley finds herself frustrated over her injuries while Skills and Mouth help Nathan find a job as a stripper in order to earn money for the senior prom. Meanwhile, Brooke betrays Rachel in order to get with a new guy and Lucas and Peyton finally reach happiness in their relationship.

A class assignment reveals the deepest secrets and desires of Lucas and the students at Tree Hill High. Worried about college prospects, Skills turns to Haley, while Nathan wrestles with Deb's suicide attempt. Chase learns that Brooke cheated on her calculus exam, while nudity and drugs run rampant in the ...