Nathan Scott is Tree Hill High's biggest basketball star and is dating Peyton, a cheerleader. Nathan's half brother, Lucas, joins the team - and threatens to take both Nathan's spot in the lineup and his girl.

Lucas plays his first game as a Tree Hill Raven...and chokes. He isn't the only one confronting insecurities: Peyton can't find the courage to submit her drawings for publication.

Frustrated by Lucas' growing popularity at school, Nathan searches for Lucas' weak spot, and has the team begin to initiate hazing incidents against him. Nathan also tries to seek tutoring help from Haley. Brooke begins to fall for Lucas. Meanwhile, Peyton is furious with Lucas for submitting her drawings to the local newspaper without her knowledge.

After Lucas crowns another good game with the winning point, Nathan switches to plan B, inviting him to a party at his dad's luxurious beach house where he cleverly humiliates him with a truth game and a video of Lucas ma calling Dan her dream husband. After Lucas walks out livid, Haley is stranded, accepts a ride back from Nathan in Peyton's car and accepts to keep tutoring him since failing grades would kill all his and Dan's dreams. On his way back Nathan crashes into Lucas in the car of one of Keith's clients; Nathan thinks he can bluff his way out making Tim his false witness, but there are nasty consequences for both brothers, their girls friends and their parents.

After the disastrous party and car crash, things still look bad for everyone. Peyton meets coach at the cemetery and exchanges grief and memories about her mother's death in a car accident the one time she ignored a red light and his late wife Camilla. With the benefit match between the Ravens boys and their fathers coming up, captained by Nathan and Dan Scott, Keith is honored to be asked as substitute by his nephew Lucas, and joins in with his mother asking him to reconsider his intent to change his last name to hers after Dan barged in at Keith's auto shop saying Lucas is unworthy of the name. At the game, Dan is the only father who can't just enjoy being creamed by their heirs- he even barges in with the boys after their glorious first half, barking so badly Keith has to defend even Nathan. Dan's behavior on the court is no more sportsmanlike, even at Nathan's expense- the golden boy's filial loyalty gets shocked in both senses of that verb.

Things are so bad between the Scott half-brothers that they are thrown off the court for rolling over the floor fighting each-other during a game in a North Carolina hick-town, Pinkerton. Brooke is hurt and scams a strong painkiller from a med student, but takes an overdose which forces Haley and Peyton to give the 'drunk' a ride; despite car trouble, they'll have it relatively easy getting back home. Coach decides to punish Nathan and Lucas by making them walk some 30 miles, which turns out just the 'fraternal' male bonding they needed as they are not given a lift but abducted by local hicks who force them to go shopping in their undershorts marked 'Ravens suck' on their backs; even after doing so, their ordeal is far from over... On the home front, Dan and Keith seize the evening without the boys to take Nathan's mother, Deb and Lucas's mother, Karen out, but land in the same restaurant where they get into a fight of their own.

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.

Brooke takes Peyton to a college party but the night takes a bad turn when someone drugs Peyton's drink. Nathan and Haley go on a scavenger hunt date set up by Brooke in an attempt to make up for her actions at the party the night before.

Tension mounts now the Ravens may get their first ever undefeated season if they win against Cove City, but instead of encouraging his son, Dan barks at Nathan he doesn't go deep enough while ordering him to convince his mother he's not unhappy, thus blaming the poor kid for her punishing him by running Karen's place. He decides to take amphetamines supplied by Tim's brother, which make him so aggressive coach throws him out at training; when he gently tries to take the next step while kissing Haley, she also shows him the door. Brooke gets Lucas to go out as 'reward' for recommending a book she lobes, then makes him drink and- get a real tattoo, to Keith's in loco parentis despair and fury. At the crucial game, Nathan's second pill dose lands him first on the bench and next in hospital. Dan doesn't believe the doctors correct substance diagnosis; he didn't even call Deb, who tells him to leave home for good.

After Peyton walked in on Lucas kissing Brooke the night she got him drunk, they all feel uncomfortable but decide to stay friends; Haley and Peyton even team up to organize live entertainment in Karen's café. Because of Nathan's pills-disaster, coach cancels basketball practice till further notice, telling livid Dan -who fears for the Ravens' shot at a perfect season- 'the game is no fun any more' so he takes off pressure. Nathan feels happy again taking things easy with Haley, but Dan decrees they're 'going to have a good time' on the golf weekend he planned with Deb till she threw him out, leaving the boy no escape from worrying about his parents plausible divorce in between humiliating golf 'lessons' in his dad's arrogant style, till he walks off shouting nobody can be happy with a bully like Dan. Jake shows Lucas why coach cuts him slack: his 6 months old baby Jenny, abandoned by her mother, and gets the advice not to keep that secret any longer. Jake uses the 'open mike' at Karen's to out his baby; afterward Lucas invites Nathan to the Rivercourt where all the kids enjoy informal basketball, putting coach and Keith's worries to rest.

After Deb drags Dan and Nathan to a family therapist, where they only fight and each expect Nathan to take their side, Nathan looses faith in everything except Haley. Brooke begins to feel jealous about Lucas, but insecure as they have almost no common interests; Lucas and Peyton both reassure her. Lucas finds Peyton's dad home for once; he tells her another, even better paid job will drag him for months to New Zealand... Nathan talks to Keith and coach, who both tell him to do what's best for him, even if that means dropping basketball; he cuts practice and classes, even takes Haley with him playing hooky, to Dan's disgust in more then one way...

On Dan's birthday, his parents turn up unannounced; Dan tries to make everybody keep Nathan's quitting from them, and Haley offers to come for moral support. Just when she was counting off her dad's return home, Peyton gets a call a storm knocked four men off his ship, and she must identify if a corps is his, so Lucas drives her, but the roads are blocked too so they must spend the night in a motel, but Lucas doesn't forget Brooke. At the Scott diner, the mothers tell the truth, how grandpa Royal Scott also pushed Dan too hard till he took his mother's advice to use a knee injury to quit basketball altogether; like coach Nathan walks out disgusted, losing all respect for the man he always tried desperately to please, and decides how to deal with it.

In therapy with Deb, who by now wants a divorce, Dan tells he cut Lucas out of his life like a trapped man amputates his arm to survive. Haley gets basketball lessons (to pass PE) from patient Nathan, who to everyone's relief is back with the Ravens. Coach tells Keith he promised his wife 35 years ago they would 'start living' after 20 years of coaching; he just won 500 matches, but what about his most important intention: to make a difference? Strolling on the beach Dan meets Carrie, who fails to seduce him when invited to eat his spare steak as Nathan declined, but just then Deb walks in. Now Brooke believes Lucas is her first true love, he and Peyton don't come clean about the motel; but Haley overhears them and has a row with him. Nathan convinces coach he does matter for boys like him who still need guidance. While driving with Lucas, Keith is hit by another car. Dan is nearby and rushes Lucas to the hospital.

When the doctor tells Keith it's too soon to tell how bad Lucas's injuries are, he informs Haley, who throws Nathan out immediately and calls Peyton, who is with Brooke at the time. A surprised Karen learns Dan saved Lucas by bringing him in and giving permission for surgery as his father, while Keith caused the accident under nearly illegal influence of alcohol. Karen and Deb comfort each-other at Lucas's sickbed, where Peyton briefly and Brooke more elaborately meet Karen. After Haley gives him the silent treatment, Nathan sadly admits to Deb he barely minds she's separating from Dan. Karen hears her insurance probably won't cover all the hospital bills, and finds out later that Keith paid the bill. Coach assures Karen not to doubt Keith's love for Lucas. Jake and the park court basketball gang make a get-better-video for Lucas; even Tim joins in making a chalk drawing on the court. Dan cancels marriage mediation, and isn't impressed by Deb's lawyer either, but gets a hug from Karen. Peyton tells Haley Lucas reads her soul. Nathan says at Lucas's sickbed he envies him sometimes and suggests he make up with his loved ones. Lucas wakes up with Nathan on his bedside. Nathan goes to get Haley, telling her he doesn't regret having courted her for the wrong reasons as she changed him for the better, then gives her a ride to hospital.

Now Lucas is out of the coma and released home, where his ma tries to make him take it easy on doctors orders, Jake brings him a games console as a get-better-and-return gift from the Ravens and uses the opportunity to get a job in Karen's café. Nathan tells his ma he understands his parents' divorce is the only option by now, and turns all his attention to Haley, who makes him realize he's not a baby who must go where he's told but can legally choose; both parents seem confident and determined to win him over, but Dan convinces him Deb doesn't stand a chance because of her secret past. Lucas has decided to break up with Brooke -but didn't tell her- sneaks out to Peyton and collapses there; he is rushed to the emergency room, Brooke finds out and faces Peyton bitterly. Although Karen is determined to repay Keith Lucas' medical bills, since Keith 'can't repay' having endangered his life, he cashes in all his savings and plans a mortgage on his garage.

Nathan must choose which parent to live with after Dan and Deb's divorce. Dan forces Nathan to make the decision by threatening to reveal Deb's darkest secrets in court unless Nathan chooses him. Meanwhile, Lucas meets a beautiful stranger who challenges his perceptions of life since Lucas' car accident.

Nathan has moved into his own apartment, away from both parents. To prepare for a match away, Coach orders Lucas to coach Nathan's weakest points, and makes them uneasy roommates; in the evening the boys sneak out but the strip joint Tim 'could get them in' turns out to be queer. Peyton and Sparkle Classic cheer-leading coach Brooke also find themselves bunking together; when Theresa falls sick, Haley is recruited and gets a crash course. Mouth spies the other teams -he demonstrates with more talent then most girls!- so they rework both choreography (Brooke) and music (Peyton); after training Brooke gets the hot pool opened, the boys jump in and coach grills chaperons Karen and Peyton's dad Larry Sawyer, but nobody minds. The new routine rocks, so Brooke wins the choreography prize. In the game Nathan uses the fade-away Lucas proposed and scores the winning point. At the home front manager Keith feels smothered by Dan and his men, and makes a drastic choice.

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 believed he saw more then an auction slave's duty when Nathan kissed Peyton, but confronted Nathan is convincingly indignant. Brooke and a test kit tell Lucas they're expecting a baby. Jake still refuses Nikki any part in Jenny's life. Nathan tells Haley he doesn't understand she won't share his bed but tattooed his jersey number on her backside. After 15 years Keith proposes to Karen, who 'isn't ready', and decides to leave. Dan tells Lucas not to let Brooke ruin his life as Karen did by having him; and bursts in at Nathan's to tell him the beach-house will be waiting 'when' he hits rock bottom.

Keith has a solicitation as auto-shop teacher in a Charleston school; Lucas is heartbroken his surrogate father may move that far away. Haley and Nathan finally feel cozy living together, but when Dan finds out he sold the car he gave his poor son, he demands the money it fetched unless he moves in with him again- so the kid chooses to stay poor and takes a lousy job serving food in the mall, where a kid he never even noticed in his history class is now the sports heroes' vindictive boss- one visit by Dan convinces even him to go easy on the long-envied golden boy whose silver spoon came at such a price, so he won't miss his own housewarming party. When he gets there, Mouths music and Nikki literally fighting with Peyton have alerted the police, so Dan -who just got in bed with Deb- gets a call from the sheriff to bail him out.

The knowledge that Dan actually requested joint custody over Lucas but was turned away by Karen makes Keith doubt her and the Scott boys, who now train together as friends, how their lives would have been growing up as brothers. Peyton and Brooke lose Jake's baby daughter Jenny in the mall, and find Nikki picked her up. Haley is furious when she finds porn sites on Nathans computer, even though everybody else considers cyber-sex innocent fun, no competition for her. Since coach Whitey must have an operation, Dan manages -to his fury- to be made Ravens coach for one match, and works the boys like a penal company. Jake thinks he'll lose a custody battle against Nikki, so he considers moving to family in Savannah and gets Peytons support. Lucas comes to a decision which worries both Karen and Keith.

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.