Season four of the hit primetime teen drama, One Tree Hill, was the first season to air on the new CW network, after The WB and UPN merged. On the new network, the series experience a surge in ratings, making it the most viewed season to date. In the fourth season, the gang is finishing up their time at Tree Hill High School.
Hayley and Nathan are pregnant, Lucas is on a mission to find out what really happened to Keith, and Peyton meets her long lost brother. Of course, nothing ever goes according to plan for this group of friends and there's plenty of drama in these twenty-one episodes.
Sad Songs For Dirty Lovers (8.8)
There is a big mystery at Tree Hill High as a calculus test was stolen from the teachers' filing cabinets and it is a witch hunt to find out which Tree Hill student stole it.
The culprit is Brooke, who has just found out that Victoria Secret wants to feature her clothing line in their stores, but she has to graduate high school first. Brooke knows if the teachers find out she stole the test, she won't graduate. Rachel is the only person who knows Brooke's secret and takes the fall for her friend.
The Ashes Of Dreams Let You Die (8.8)
Lucas has figured out that it was Dan who shot Keith, not Jimmy. In this episode, Lucas walks in on his mom, Karen, and Dan kissing and he immediately gets upset.
He tries to tell people the truth about what happened to Keith, but because he has no proof, no one will believe him. At school, Peyton tells Brooke she has been offered a summer internship at a record company in Los Angeles and now she has to find a way to tell Lucas the big news.
I Love You But I've Chosen Darkness (8.9)
Peyton has been getting close with her half brother, Derek, but Lucas has his suspicions. It turns out, Lucas was right to be worried about the stranger who showed up claiming to be Peyton's family because he's not.
Derek is actually a stalker and has been watching Peyton on her webcam and became obsessed with her. Everything comes to a head in this episode has Derek attacks Peyton, who is eventually saved by Lucas and Peyton's real brother, Derek.
Song To Love And Die By (9.1)
Nathan gets involved with a bad guy name Dante, who asks Nathan to throw a basketball game so he'll win a bet. When the Ravens win the game, Dante comes after Nathan, but instead, hits Hayley with his car.
Lucas rushes to Hayley's side and goes into cardiac arrest. Both Lucas and Hayley fight for their lives in the hospital and while unconscious, Lucas is visited by his Uncle Keith who shows Lucas what Tree Hill would've been like if he wasn't such a good guy.
Prom Night At Hater High (9.1)
Brooke and Nathan must deal with the repercussions of their sex tape being released during a party the night before prom. No one ever knew that Nathan and Brooke spent a night together and it was a very long time ago, but it still upsets both Hayley and Peyton, who was dating Nathan at the time of his encounter with Brooke.
Now, Brooke must put a smile on for prom night, pretending the tape never happened, which is even harder due to the fact that her new love interest and prom date is a "clean teen".
The Birth And Death Of The Day (9.1)
It's graduation day, which of course, doesn't go smoothly. After Lucas confronts Dan about killing Keith, Karen collapses and his rushed to the hospital, where both her life and the life of her and Keith's unborn child, hang in the balance.
Lucas' friends convince him to go to graduation knowing he'll regret it if he isn't there and he agrees. Hayley gives her valedictorian speech, but in the middle of it, starts breathing heavily and announces that she thinks she's in labor.
You Call It Madness, But I Call It Love (9.2)
This episode opens with Lucas arriving at Peyton's house to pick her up for prom. Previously, Peyton told Lucas that she didn't want to go to prom after seeing the tape Brooke and Nathan made while Nathan and Peyton were still dating.
When Peyton doesn't answer the door, Lucas leaves, assuming she meant it when she said she didn't want to go, but actually, psycho Derek as returned and is holding Peyton hostage in her own home.
Pictures Of You (9.4)
One of the teachers at Tree Hill High School asks the students to pick a partner out of a hat and spend the day getting to know that person.
At the end of the day, the partners have to take a picture of one another and the picture should represent who they really are and show them in their best light, with these photos eventually going into the yearbook. The core friends on the show end up getting to know more about their classmates who they don't spend as much time with.
All Of A Sudden I Miss Everyone (9.5)
The beginning of this episode shows both Karen and Hayley in the hospital, being brought into separate rooms. Hayley is giving birth to her and Nathans's son, as Karen clings to life after giving birth to her and Keith's daughter. The episode flashes forward to a few months later where both new moms are healthy and home with their children.
At the same time, Dan sits in a jail cell after having confessed to killing Keith. Karen visits Dan in jail, just to spit on the door of his cell.
Some You Give Away (9.7)
It's the State Championship game and also Whitey's last game as the coach of the Tree Hill Ravens. Dante has asked Nathan to throw the game, itting that he chose Nathan for the task knowing that he was Dan Scott's son and assumed he didn't have a soul.
Nathan can't throw the game and the Ravens are victorious after a game-winning basket by Lucas. As the team celebrates, Lucas tells Peyton he wants her by his side when all of his dreams come true.