Plot
Danielle, Tiffany, and Brooke are the three richest, most popular girls in their high school, nicknamed "The Huns" due to their exclusive housing estate, Hundred Pines. Danielle and Tiffany are cruel and spiteful, whereas Brooke is kind but is easily intimidated and manipulated by Danielle and Tiffany. While the leader Danielle is used to getting what she wants, she is unable to attract lonesome ex-jock Drew due to his mourning over the death of his girlfriend Charity Chase. Although Charity was believed to have committed suicide, this wasn't the case as Danielle, Tiffany, and Brooke lured Charity to a cliff, hoping to terrorize her into breaking up with Drew, but ended up killing her by accident.
A year to the day of Charity's death, Romanian foreign exchange student Katarina arrives during the class of clumsy Media Arts Professor, Mr. Chauncey. Katarina and Drew immediately become friends. Jealous of this, Danielle tries to do everything in her power to stop this friendship from developing into love. In an attempt to get close to Drew, Danielle works at the elderly home where Drew is also working. While there, she is assigned to look after an old lady whom she believes is catatonic. Danielle, Tiffany, and Brooke use this opportunity to raid the old lady's cupboard and eat her box of chocolates.
In the following two weeks, the three girls begin to notice that something strange is happening to them, they are receiving back pains and their hair is turning gray - to their horror they discover that they are aging at a rapid speed. Danielle is suffering from bladder atrophy which leads to her constantly wetting herself and eventually wearing adult diapers, while Brooke has a chronic gas problem on account of her fiber diet. Tiffany's eyesight is also damaged and she is forced to wear glasses. They believe this has something to do with Katarina whom they now think is, in fact, Charity's ghost coming back to seek revenge. The three decide the only way to regain their youth is to kill Drew to let his spirit be with Charity. At Danielle's 18th birthday party, the three lure Drew to the same gorge where Charity died and attempt to shoot him. Katarina shows up and says she is not Charity's ghost. Danielle briefly ponders this but decides to shoot them both anyway. However, Brooke finally stands up for herself and says that they have gone too far, admitting that she lived in poverty and managed to join the Huns after winning US$56M in the local lottery. She tries to prevent Danielle from pulling the trigger to which Drew disarms her. Danielle shoots Katarina's wrist and she bleeds, meaning she is not a ghost. Unfortunately, due to Danielle being frail and also distracted by a party guest dressed in a clown suit from her party (who is secretly Chauncey eavesdropping on them the whole time) who she shoots along with Katarina, both Tiffany and Danielle are overcome from exhaustion.
Now in the old age home, Tiffany is hooked on a life support machine and Danielle is barely alive, implying it is far too late to be cured. At that moment, Mrs. Witt (the old woman who Danielle was meant to be caring for) shows up and reveals that she is Charity's grandmother. Also, while she had been briefly unable to speak due to a stroke, she had very good hearing and sight and overheard Danielle bragging about Charity's murder. Witt then reveals she poisoned the chocolate box (knowing that the girls would eat it) with an aging chemical (thanks to her late roommate's husband who worked with biological warfare technology); Brooke wasn't dying as she demonstrated self-control while Danielle and Tiffany had eaten most of the poisoned chocolate. Tiffany presumably dies during Witt's revelation, and Danielle flips the bird to Witt in response and then dies shortly afterwards.
At Danielle and Tiffany's funeral, everyone is in attendance, including Drew and Katarina (now an official couple). Brooke is also in attendance after a plastic surgeon's operation to try and improve her appearance, but only so much could be done and she still looks fifty years old. Chauncey forgives her as he knows she wasn't as cruel as Danielle and Tiffany, and she regrets what she has done. Danielle and Tiffany are then revealed to be in a luxurious room with their youth restored and are convinced that they are in heaven. But it is revealed that they are actually in hell as they are forced to forever endure the company of their school's most annoying dork, Jonathan Wharton, who is completely devoted to Danielle's every move. As such, he reveals that he committed suicide just to be with her forever and briefly morphs into the devil, much to her and Tiffany's chagrin and horror.
