Rebellious teen Amy defies her parents by going to a trashy carnival that has pulled into town. In tow are her boyfriend, Buzz, and their friends Liz and Richie. Thinking it would be fun to spend the night in the campy "Funhouse" horror ride, the teens witness a murder by a deformed worker wearing a mask. Locked in, Amy and her friends must evade the murderous carnival workers and escape before it leaves town the next day.
A loving father finds a clown suit for his son's birthday party, only to realize the suit is part of an evil curse that turns its wearer into a killer.
The clumsy and unfunny clown Richard "Stitches" Grindle entertains at the 10th birthday party of little Tom, but the boy and his friends play a prank with Stitches, tying his shoelaces. Stitches slips, falls and dies. Six years later, Tom gives a birthday party for his friends at home, but Stitches revives to haunt the teenagers and revenge his death.
After picking up a traumatized young hitchhiker, five friends find themselves stalked and hunted by a chainsaw-wielding killer and his family of equally psychopathic killers.
When a creepy Jack-in-the-Box is discovered and opened on the grounds of an exclusive girls' school, six brave students soon enter a fight to the finish against the unleashed demon.