One Tree Hill - Season 4 | Updated

: Peyton is targeted by a "Psycho Derek" (Ian Banks), who impersonates her biological half-brother. She eventually meets her actual brother, a Marine also named Derek, who helps her confront her trauma.

: Brooke moves in with Rachel Gatina, faces a cheating scandal on a calculus exam to ensure she graduates, and begins a relationship with a "Clean Teen" named Chase Adams. Key Episodes One Tree Hill - Season 4