Sara is about to move out and live with Irene her older friend, and keep the cat, so Rebecca decides to put the poor little thing into the dryer. When Sara returns to the room she tells her that little Cuddles is missing. Sara goes off to look for it. Meanwhile Rebecca beats herself up, blaming a hobo, to blackmail Sara to not leave her alone anymore.
A little later, the art lecturer (Billy Zane) tells Sara about an event over Paris where he has the budget to take one lucky student - and then makes a move on her. She leaves immediately, and tells Rebecca about it.
Rebecca drops round Billy's office to seduce him, which works, and she records a scene on a mini voice recorder. She beats him up (this girl is tough), leaves, and after it is played to the Dean he is suspended.
Rebecca invites Sara back to her LA mansion for Thanksgiving, where she meets the nervous parents for the first time. Discreetly, they ask Sara if her roommate is taking her medication. Finally, Sara realises that something is not quite right with her friend.
Back in the dorm, Rebecca escapes for the night to hit on Irene, guessing that she is a lesbian. And for someone who hates clubs and dancing she pulls out quite a few moves. Sara seizes her opportunity to rummage through Rebecca's stuff and finds the pills, unopened.
When Rebecca returns the next day, Sara is ready to tell her that she is moving out, but doesn't get a chance. Instead Rebecca asks her first to go with her so she can get a tattoo. They go to the parlour, Rebecca chooses the design and then shows her roommate - it's a replica of Sara's - the name "Emily" on her chest. Sara is mad and runs out.
She packs, but can't find her necklace. She leaves and moves in with Stephen in the frat house. Jason the ex-boyrfriend show up and leaves a note.
Rebecca takes crazy to the next level. She dyes her hair to look like Sara and drops round Jason's hotel room. She is seducing him, disguised as Sara, when she takes out a tiny art blade and stabs him.
Sara gets a message from Irene that she is back in town and wants her over, see tells Stephen and heads round.
At Irene's apartment the door is opened - and inside Irene is tied to the bed. Rebecca appears with a gun, gives a speech about how she just wants to be her friend and should be thanked for all she's done. Stephen shows up. They fight for the gun, he's smacked over the head soon enough.
Next Sara and Rebecca fight it out WWE style. Rebecca is locked out and Sara tried to escape out the window - but Rebecca still has the gun, shoots her way in, and Sara is left to hang precariously from the curtains. Stephen comes to the rescue and punches Rebecca out cold. He pulls Sara back inside.
But wait - Rebecca sits up straight and again someone is knocked out - this time it's Stephen. Again. Looks bad this time. Sara grabs the gun and shoots - but it's empty.
Rebecca tries to strangle Sara, but she manages to fumble around and find the art blade that she stabs into her ex-roommate's back. She gets back the necklace. But wait - Rebecca is still alive ... then she dies.
As it ends, Sara moves into a new dorm - but to avoid any confusion, you can't trust these penny-pinching uni's, with Stephen they push the other bed out the room and leave it in the hallway.