As Nathan, Rachel and Cooper's lives remain precarious following the car accident, Brooke celebrates her 18th birthday but finds it diminished by her struggles with Peyton. Lucas and Karen come to terms with her pregnancy and with the pregnancy of someone close to Lucas, while Deb's past addictions intersect with Haley in an explosive manner.

Peyton introduces hip-hop sensation Lupe Fiasco at Tric, while rumors that Brooke is pregnant run rampant. Still dealing with their car accident, Nathan buys a motorcycle despite Haley's reservations, and Rachel poses for Maxim magazine. Meanwhile, Lucas clashes with Derek, and Deb double-crosses Karen.