"Pilot" is the first episode of One Tree Hill's first season. It first aired on The WB television network in the United States on September 23, 2003. It was written by Mark Schwahn and directed by Bryan Gordon. It saw John Keenan and Melissa Claire Egan guest star as Officer Wayman and Melody, respectively. It introduces the character of Lucas Scott — a high school student — and his friends and relatives in the fictional Tree Hill, North Carolina.

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.

Nathan is concerned about Lucas' health, so he tells Karen that Lucas didn't take the heart test. Dan offers Keith to continue working at the dealership-as vice president. At school, Peyton must confront the rumors going around that she is a lesbian. This affects her friendship with Anna. As for Nathan and Haley, they begin to grow apart...

As his marriage with Haley continues to go wrong, Nathan goes into a emotional crisis and becomes the "bad" Nathan of the past. Karen continues to struggle and try to figure out what would cause Lucas to move in with Dan. Peyton and Jake's relationship gets greater.

Keith gets violent with Dan after learning that Dan paid Jules to fall in love with Keith. Anna turns Felix in to the school authorities after learning that he was the one who vandalized Peyton's locker. Lucas and Brooke discuss Brooke's possible move. Meanwhile, Nathan chances Haley in the hope of bringing her home. Brooke decides to move in with Karen.

When someone unleashes the students' time capsule upon Tree Hill High, Lucas and Mouth must confront a person from their past. Brooke has to deal with the revelation that secrets aren't the only things she exposed in the time capsule. Dan learns to forgive Keith. Haley is forced to reconcile the man Nathan was before with the man he has become, and Peyton's Breast Cancer Benefit Concert at Tric features performances by Haley, Jack's Mannequin and the return of Fall Out Boy.

Due to the aftermath of the release of the time capsule, chaos breaks out. Someone is holding students of Tree Hill hostage with a gun, shooting. While lives hang in the balance, Nathan and Lucas put themselves at risk to protect their friends and loved ones. Young lives are shattered and two lives will end.

Nathan gets two surprises in a row, and everyone is eager to share their advice with him. Deb also shares something she picked up. Brooke decides to celebrate while Peyton is being attacked by her stalker.

Peyton returns to school, but she breaks down. In the meantime Nathan is cornered into a no-win situation by Daunte. Brooke's fashions are a hit at the local show. And Deb takes drastic action for her addiction.

Derek tells Peyton to give Lucas a chance just as Brooke tries to make up with him. Rachel asks Haley to tutor her when she discovers she is failing a class. And Nathan has more trouble with Daunte.

The aftermath of the series of unfortunate events at Tree Hill begins. Lucas returns to his everyday life, following his heart attack, and tries to rekindle his relationship with Peyton. However, things are rougher for Haley when she discovers that Nathan had more involvement in her accident than she could have ever imagined.

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.

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.

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 to win over Karen's affections.

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 with theories about Keith's murder.

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

Haley tries to make Nathan understand what is going to happen if he doesn't change his ways. Lucas and Skills prepare James 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.