Aside from a love for hoops, it would seem that Lucas and Nathan are two young men with little in common, but they are bound by the dark secret that they share the same father. Arrogant and assured, Nathan is the star of the high school basketball team and hails from a wealthy family. Quiet and driven, Lucas is the only child of a single working mom. Now the two boys' lives collide when a twist of fate puts Lucas on Nathan's team and the half-brothers compete, not only for control of the court, but also for the heart of Nathan's beautiful girlfriend Peyton. Years in the making, a deep and bitter conflict slowly unfolds as the two boys struggle to come to terms with who they really are, and a father who has chosen to live vicariously through one son, while ignoring the existence of the other.
Aside from a love for hoops, it would seem that Lucas and Nathan are two young men with little in common, but they are bound by the dark secret that they share the same father. Nathan is the star of the high school basketball team and local town hero, while Lucas is the only child of a single working mom. Now the two boys' lives collide when a twist of fate puts Lucas on Nathan's team and the half-brothers compete, not only for control of the court, but also for the heart of Nathan's beautiful girlfriend Peyton.
Lucas blows his first Varsity game and decides to quit the team. The wedge between Nathan and Peyton continues to grow after Peyton tires of Nathan's jabs at Lucas. Meanwhile, Keith forces Karen to deal with her feelings for Dan after she refuses to step foot in the high school gym to support her son.
Frustrated by Lucas' growing popularity at school, Nathan searches for Lucas' weak spot, and finds it in Haley. Meanwhile, Peyton is furious with Lucas for submitting her drawings to the local newspaper without her knowledge.
Haley convinces Lucas to go with the team to an after-party at Nathan's beach house in the hopes that the guys will become closer. When Lucas sees the wealth that was denied him, he finally confronts his mother about why she let Dan ignore them. Meanwhile, when Nathan's mom returns home to find a very angry son, she turns to Karen for advice.
Lucas asks Keith to play with him in the annual "Father and Son" basketball game, and realizes he got the better father figure after Dan publicly humiliates Nathan on the court. Also, Peyton has a hard time dealing with the anniversary of her mother's death and finds a comforting ally in Whitey.
When Whitey throws Lucas and Nathan off the bus due to their misconduct on the basketball court, not only does it leave the two brothers stranded 30 miles from home, but they encounter a carload of punks who threaten them with a gun. Injured during the game, Brooke needs Peyton to drive her home and in, an unlikely turn of events, Peyton asks Haley for help. Meanwhile, Karen and Keith attend a business function and tempers flare when Dan and Deb are seated at their table.
On the night of Dan and Deb's annual basketball appreciation party stirs up old wounds and new feelings as Karen makes a new friend, Keith faces off with his younger brother once again and Lucas finally makes his move on Peyton. Also, Haley and Nathan grow closer until Brooke spreads a vicious rumor that leaves Haley devastated.
Looking for some fun, Brooke and Peyton crash a college party, but things turn ugly when one of the guys in the dorm, Gabe drugs Peyton. After Brooke calls Lucas for help, the two bond over caring for a sleeping Peyton, prompting Lucas to look at Brooke in a new light. Meanwhile, Haley gives Nathan another chance and the two go on their first date.
After fighting with his father and Haley, Nathan succumbs to the pressure he is feeling and takes amphetamines to help his game. However, he isn't prepared for the destruction the drugs do to both his body and his family. Meanwhile, Peyton goes to Lucas to rekindle their relationship, but when she arrives at his house, she catches him with Brooke.
After Whitey cancels basketball practice, Brooke convinces Lucas to let loose and takes him out for a wild night out on the town. Meanwhile, Deb instructs Dan to take Nathan away for a father-son weekend to try and rebuild their relationship, but things don't go exactly as she had hoped.
Unable to handle the pressure from Dan, Nathan decides to quit the basketball team and looks to Haley to help him fill his free time. Meanwhile, Brooke becomes increasingly jealous of Lucas and Peyton's growing friendship.
After Peyton receives the devastating news that her father is lost at sea, she and Lucas take an overnight trip to Hilton Head to identify a body that has washed ashore. Overcome with emotion, Peyton kisses Lucas. Meanwhile, an unexpected visit from Dan's parents leaves the Scott family in turmoil as numerous family secrets are revealed at Dan's birthday dinner.
On their way to pick up Karen from the airport, Keith and Lucas' car collides with an oncoming vehicle and an unconscious Lucas is left fighting for his life. Having witnessed the accident, Dan races Lucas to the hospital and must acknowledge that Lucas is his son in order to save his life. Meanwhile, Peyton decides to tell Brooke about the kiss she and Lucas shared.
While holding a vigil at Lucas' bedside as he lays in a coma, Karen meets her son's new girlfriend and learns from Deb that she is divorcing Dan. Most shocking of all, Karen is horrified to discover that Keith was drinking while driving at the time of the accident. Meanwhile, Nathan tries to win Haley back after she dumps him.
After his near-death experience, Lucas decides he made the wrong choice between Brooke and Peyton so he breaks things off with Brooke and secretly rekindles his romance with Peyton. However, the truth becomes obvious after he is rushed to the emergency room again and the girls come face to face in the hospital. Meanwhile, unable to pay his mortgage after paying Lucas' hospital bill, Keith puts his garage up for sale.
Nathan must decide which parent to live with after the divorce, but Dan decides to force his hand by threatening to reveal Deb's darkest secrets in court unless Nathan chooses him. Meanwhile, Lucas meets a beautiful stranger who starts his head spinning. Grammy Award-winner Sheryl Crow appears as herself and performs the song "The First Cut Is The Deepest" in Karen's Cafe.
The gang hits the road to Charlotte where Brooke is determined to win first place at the annual cheerleading competition, but when one of her squad falls ill, Peyton begs Haley to step into the cheerleader's shoes for a day. Meanwhile, after Whitey assigns Lucas and Nathan to the same room, tempers flare and Haley is caught in the middle.
Lucas, Nathan and Jake are auctioned off to the highest bidder in the annual "Boy Toy" charity auction and the night leads to surprising developments with old flames. Meanwhile, having missed out on the auction, Brooke ends up with Mouth and gives him the night of his life.
Lucas must make a difficult decision regarding Brooke. Haley considers having sex with Nathan.
While Nathan looks for an after-school job to pay his rent, Haley decides to throw a party at his apartment but panics when things get out of control. After a jilted Brooke realizes she was not invited to the festivities, she decides to crash the party with her new friend Nicki.
Lucas is shocked to learn that Dan once asked Karen for joint custody of Lucas when he was a baby. Meanwhile, Peyton panics after Nicki kidnaps Jake’s baby while she is babysitting.
Lucas and Nathan bear the brunt of Dan's abuse as he coaches them into the playoffs, pushing both of them to their breaking points. Haley is stunned after Dan threatens her, causing her to reconsider her relationship with Nathan. Meanwhile, Whitey learns that his medical condition may be more serious than he first expected, and Dan learns a shocking secret from Deb.