Needy je nevpadljiva srednješolka, Jennifer pa njena neustavljivo zapeljiva najboljša prijateljica in najbolj popularna punca na šoli. Nekega dne se zgodi požar, ki mu sledi več umorov. Needy je vse bolj prepričana, da se je v Jennifer naselil demon in jo spremenil v pošast, ki z lepim telesom svoje sošolce najprej zapelje, nato pa jih pokonča. Needy se zaveda, da mora ukrepati, da bi rešila mesto in svojega fanta.
Nerdy, reserved bookworm Needy Lesnicki, and arrogant, conceited cheerleader Jennifer Check are best friends, though they share little in common. They share even less in common when Jennifer mysteriously gains an appetite for human blood after a disastrous fire at a local bar. As Needy's male classmates are steadily killed in gruesome attacks, the young girl must uncover the truth behind her friend's transformation and find a way to stop the bloodthirsty rampage before it reaches her own boyfriend Chip.