Nathan worries about Haley as they prepare to renew their vows. Peyton and Brooke's friendship becomes strained and Deb confesses to Dan about the fire.

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.

The Tree Hill residents are forced to face their fears as Dan turns over on a new leaf and Brooke taking the hardest decision of her life. In the meantime, Haley's career takes a turn and Peyton is visited by somebody from her past. Mouth and Millicent meet a new face. With all, Lucas and Brooke help each other through the struggles.

Brooke is shocked to find out that Samantha is in her room with a boy named Jack. Along with that, Julian asks her to make some clothes for the movie. Peyton tries to get Mia to focus on her follow-up album. Lucas is excited when he travels to Hollywood to meet the director of the movie. Meanwhile, Nathan gets the chance for a pro-basketball try-out. Haley takes Jamie to his school's talent show and Millicent confronts Mouth about Gigi.

Tree Hill bids goodbye to the past while anticipating the future: Lucas and Peyton prepare for the birth of their child with the help of a surprise visitor, Dan nears his end, and Brooke works with Victoria to relaunch Clothes Over Bro's. Meanwhile, Nathan returns to Tree Hill to face Haley and Jamie after being released from the Chiefs.

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.

Haley tries to overcome her depression by joining Nathan, Jamie and the rest of the Tree Hill gang on a trip to Utah for the premiere of Julian's film.

As the gang returns from Utah, Brooke and Julian are engaged, Haley learns that she is pregnant, Nathan must leave for training camp, and Clay and Quinn are assaulted and shot by Katie.

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

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.

As Brooke and Haley prepare to re-open Karen’s Café, Nathan and Clay hit the road looking for new prospective clients. Meanwhile, Chase leaves for the Air Force leaving behind a disappointed Alex and Chuck, and Mouth and Millicent begin their new morning show together.

As Brooke and Julian begin to adjust to life with their new children, Haley and Nathan find themselves dealing with similar issues. Although they don't know it yet, faces from the past threaten to interrupt plans for all their futures. Meanwhile, a mysterious problem arises for Clay and Quinn.

Dan, Julian and Chris Keller attempt to rescue Nathan. Brooke’s conflict with Xavier escalates. Quinn and Clay revisit the past.

In the final chapter of One Tree Hill, the tenth anniversary of Tric brings old faces and new possibilities for the Tree Hill family.