"With Arms Outstretched"
Lucas starts dating Brooke, though Peyton is clearly in love with him.
"Life in a Glass House"
The audience finally learns Jake's little secret: he has a daughter.
"Crash Course in Polite Conversations"
Lucas cheats on Brooke with Peyton.
"Hanging by a Moment"
Keith and Lucas get in a car accident on the way to pick Karen up from the airport, leaving Lucas in a coma.
"To Wish Impossible Things"
Nathan strips for the annual "Boy Toy" charity auction.
"The Games That Play Us"
Nathan and Haley elope.
"The Games That Play Us"
Dan suffers a heart attack after discovering that his wife Deb slept with his brother Keith.
"Don't Take Me for Granted"
We find out Jules is working for Dan as part of his revenge scheme on his brother, Keith.
"The Hero Dies In This One"
Haley leaves Tree Hill to go on tour with Chris Keller.
"I'm Wide Awake, It's Morning"
Nathan crashes a race car while visiting his Uncle Cooper.
"The Leavers Dance"
Dan is drugged while his car dealership is set on fire with him still inside.
"A Multitude of Casualties"
Both the basketball teams and the cheerleading squads get into a rumble during "Midnight Madness."
"With Tired Eyes, Tired Minds, Tired Souls, We Slept"
The school shooting episode leaves a student dead from suicide and Peyton injured from a bullet to the leg. Dan shoots his own brother Keith in the chest, killing him.
"The Show Must Go On"
Nathan and Haley get married again, but their wedding day ends in tragedy when a car accident leaves Nathan, Uncle Cooper and Rachel's lives in danger.
"I Love You But I've Chosen Darkness"
Peyton is attacked by someone posing as her brother ("Psycho Derek"), but her real brother saves her in the nick of time.
"I Love You But I've Chosen Darkness"
Haley tells Nathan she's pregnant, seconds after he tells her he's been offered a basketball scholarship to Duke.
"Some You Give Away"
Lucas finally admits his love for Peyton after the Ravens win the state championship.
"Some You Give Away"
Haley is run over by Daunte, who was aiming for her husband Nathan. Lucas suffers a heart attack after arriving at the scene of the accident.
"You Call it Madness, But I Call it Love"
Psych Derek returns and holds Peyton and Brooke hostage in Peyton's own house.
"The Birth and Death of the Day"
Haley goes into labor while giving her Valedictorian speech.
"All Of A Sudden I Miss Everyone"
Dan confesses to murdering his brother Keith and goes to jail.
"4 Years, 6 Months, 2 Days"
Four years later, Nathan is in a wheelchair and battling alcoholism.
"Hundred"
Lindsay leaves Lucas at the altar after realizing he's in love with Peyton.
"Touch Me I'm Going to Scream, Part 1"
It's revealed that it was Peyton that Lucas called from the airport and proposed to.