Lucas investigates Dan’s heart condition. Haley struggles with letting Dan into Jamie’s life. Peyton also still struggles with her guilt over Lucas’ breakup and Mouth finally gets the chance to be a sports anchor.
The Tree Hill residents are forced to face their fears as Dan turns over on a new leaf and Brooke makes the hardest decision of her life. In the meantime, Haley’s career takes a turn and Peyton is visited by somebody from her past. Lucas is still struggling to mend his heart after Lindsey left him at the alter. Mouth and Millicent meet a new face. With all, Lucas and Brooke help each other through the struggles.
Lucas is crushed by devastating news. Quentin is pushed to his limits during a Ravens game. Dan’s is second on the donor recipient list to get a new heart. Haley thinks about her decision to release a new album while Brooke’s baby undergoes emergency surgery and a shocking truth stuns Peyton, told by Lucas.
Lucas investigates Dan’s heart condition. Haley struggles with letting Dan into Jamie’s life. Peyton also still struggles with her guilt over Lucas’ breakup and Mouth finally gets the chance to be a sports anchor.
Nathan and Haley throw a birthday party for Jamie. Deb hired a clown, and Haley is not happy with it since it’s a creepy one. Lindsey returns to Tree Hill for Jamie’s birthday, which gives Lucas hope that the relationship will be rekindled. When Dan arrives, Deb’s mood swings fast and in the meantime Brooke and Peyton attend the party with baby Angie.
Not to have a repeat performance, Nathan and Haley interview nannies, with no such luck. Brooke is undeterred when adopting, and she is given a second chance to prove herself to the adopting agency. Mouth is given a chance to have a permanent sports spot in Omaha, which forces Mouth and Millicent to make a decision about their relationship. Meanwhile, Quentin is making trouble with the Ravens coaches.
Lucas is distraught after being being dumped at the altar, while Nathan and Haley go to counselling to work out their marital problems, with surprising results. Dan is a free man, but he runs into a dead end trying to readjust. Brooke is asked some difficult questions while being interveiwed to be an adoptive mom. Meanwhile, Peyton gets a visit from her old friend, Max the old owner of the infamous Tree Hill music shop.
The big day for Lucas and Lindsey’s wedding has arrived. Nathan attempts to reconcile with Haley, with no avail. Peyton sees her last chance to get her man as Lucas says “I do”. Meanwhile, Dan and Nanny Carrie have dark intentions.
On the eve of Lucas and Lindsey’s wedding, they conspire to save Nathan and Haley’s marriage; Brooke pairs Peyton with an old boyfriend; Rachel and Dan return to Tree Hill.
Brooke runs into someone from her past while on a trip to New York with the Tric bartender, Owen. Nathan and Lucas attend Dan’s hearing while they try to protect Jamie from him. Mia gets an offer from a major record label and in the meantime, Haley and Nathan’s marriage is on the rocks.
Haley, Brooke, Peyton, Lindsey and Mia get locked in the Tree Hill High library; Brooke tries to stand up for her mother; Lucas and Nathan try to tell their loved ones about their indiscretions.
Brooke continues to pursue Owen. Carrie continues to flirt with Nathan. Haley is upset at Lucas and Peyton for what happened the other night. Quentin needs to change his negative approach in order to succeed in the season-opening game. Mouth tries to win Millicent back.
The Honorary Title performs at Tric and Mia plays her song there as well. Carrie tries to get closer to Nathan. Brooke sets Mouth up on a blind date with her assistant and Lindsey confronts Lucas about Peyton.
It’s confrontation time in Tree Hill, as Lucas confronts Peyton about her nasty behavior towards Lindsey and Brooke must confront Victoria about meddling with Peyton’s record label. Meanwhile, Nathan begins to grow closer to Carrie, Haley continues to struggle in dealing with Quentin, and Mouth must choose sides between his co-workers and Alice.
In this flashback episode, memories are looked back upon. Lucas surprises Peyton in Los Angeles and they talk. He asks her something and is left with a surprising answer. Meanwhile, Nathan’s temper triggers up after a guy reminds him of his cheating in high school basketball games.
Peyton wants Haley to work with Jason on his music but he refuses to. Mouth is involved in a relationship with his boss and age is a factor in it. As the opening of Clothes over Bros approaches, Brooke finds herself in a few problems. Nathan takes strides to help Quentin.
Now that Peyton and Brooke are back in Tree Hill, Lindsey worries that the two might threaten her and Lucas’ relationship. Meanwhile, Nathan visits Dan in prison (his first visit in four years) and gives him a picture of his grandson. Meanwhile, Haley tries to persuade Quentin to return to school, Brooke opens her store in the old Karen’s Cafe and Peyton signs her first band.
Haley tries to make Nathan understand what is going to happen if he doesn’t change his ways. Lucas and Skills prepare Jamie to compete in a race-car competition. Meanwhile, Brooke faces problems at her company and Peyton meets Lucas’ new girlfriend. Mouth gets a job, but it doesn’t turn out well.
It’s four years into the future and the Tree Hill gang has finished college. Now, their lives have taken completely different directions. Lucas has written and published a book, Brooke has made it big in the fashion industry with her brand “Clothes Over Bro’s”, Peyton is pursuing a career in the music business, and Nathan and Haley continue to raise a now older James.
Summary: Locke tasks Sawyer with a mission, and Kate talks to Locke while holding a fake, plastic gun while Sayid is watching them.
Summary: Members of the sales staff let Sabre’s new Sales Is King policy go to their heads.
Summary: A high school senior repeatedly hallucinates after blacking out during a class trip; Wilson tries to furnish his condo.
Summary: The team reopens the case of a dock worker, who moonlighted as a professional wrestler, who was shot dead in 1986; Valens secretly looks into a lead on the man who mugged and raped his mother.
Summary: Casey carries out a side mission for his old commanding officer James Keller that leads to him committing treason. When Chuck learns the dark truth about Col. Keller, he and Sarah set out to break Casey out of jail and clear his name. Meanwhile, Awesome’s plan to keep Ellie out of danger gets more difficult when she gets her dream fellowship.
Summary: Kitty’s popularity surge creates havoc for her family; Luc faces the possibility of deportation; Nora reaches out to Tommy for help.
Summary: Naomi goes on her first hike with Ivy and Liam; Annie gives Jasper an ultimatum; Gia and Adrianna’s friendship grows.
Summary: Liz keeps running into Wesley (Michael Sheen), causing her to question their decision; Jack tries to secure his position in the new company.
Summary: While Jack and Cole team up in the field to shield New York from the calamitous threat, a hostage situation has CTU completely stressed out. Meanwhile, unrelenting parole officer Prady presses on in his investigation, and unexpected developments send the Hassan family into a major tailspin.
Summary: Rufus and Lily grow suspect of Jenny’s relationship with Damien. Chuck learns more about the woman who may or may not be his mother. Dan and Vanessa struggle through the awkwardness of dating other people.