You Call It Madness, But I Call It Love(Season 4, Episode 16)

Psycho Derek has Peyton tied up in her basement, groggy from a sedative. BUT WAIT! Didn't Peyton tell Lucas a few episodes ago that she got a call from the cops saying he was apprehended? Well, that call was actually from Psycho Derek. It seems kind of strange Peyton wouldn't have followed up on that just to make sure, but she wasn't exactly in the right frame of mind,I guess. Lucas shows up to take Peyton to the prom, but leaves when she does not answer the door.

Psycho Derek decides to have his own prom with Peyton. He has a tape of her voice saying his name on a continuous loop.

Rachel did not leave on the plane! She shows up at the prom, but the dick principal won't let her in on account of the expulsion and all. Rachel makes an open invitation to everybody to party in her limo, and Mouth takes her up on that shit right away! Brooke has gone to try to make up with Peyton. Boy will she be surprised!

Mouth has Rachel all to himself but can't stop talking about nutty Shelley. Rachel pretty much tells him this exact thing! She regrets that she was too late to take Mouth's virginity.

Lucas and Haley break down on the way and must get a ride from Debra. A dorky kid spikes the punch bowl and Nathan physically assaults him for inadvertently threatening Haley's baby. Haley tells Nathan to chill out already. The kid gets bombed out on his own concoction and the principal makes Haley and Nathan drive him home. Good Lord. I mean, why? Why? Anyway, the kid wakes up in the back seat and starts giving Nathan grief, so he's forced to walk home. A just punishment.

Dan discovers a mysterious note on the floor meant for Karen(it reveals that Dan killed Keith.) I suppose this means that his tormentor is a student attending the prom?

Brooke wanders(blunders?)into Peyton's basement and is captured by Psycho Derek. Even in this dire situation the two of them can't stop squabbling, and Derek offers to murder Brooke to show his love for Peyton. Peyton convinces Derek to untie her so she can kill Brooke herself. Derek obliges and Peyton start slapping poor defenseless Brooke. I hate this!

Derek gives Peyton a knife to finish Brooke off, but Peyton plants it in his upper chest area instead. She was only acting! I was worried. Derek chases Peyton upstairs , but Peyton is waiting with her boxing gloves on  and proceeds to beat the shit out of Derek. She is soon joined by Brooke, and the poor bastard doesn't stand a chance. It's pretty glorious, really. Derek is last seen being placed in an ambulance on a gurney. It's nice Brooke and Peyton could put their differences aside to put the bad guy in a coma.

Rachel must leave(for real this time)so she dances with Mouth in the terminal. BUT PLOT TWIST! She asks Mouth to go with her and he does! That is some very risky business.

CLIFFHANGER! Dan has received a taunting text message. He dials the number of the phone, and finds it it on the floor of the hallway where he murdered Keith. Lucas has come her too, to jog his memory, and Dan snaps at Lucas to accept that Keith is gone. Dan tells Lucas to "open his eyes" the same words Keith told him in the after life. This finally causes Lucas to remember something about the day of the shooting: Abby(the girl with the diabetes!)was hiding in an office peering at him through some closed blinds!

Battered and bloody Brooke shows up(with Peyton!) to the prom just in time to win Prom Queen. Who else was it going to be?