Damn fine horror film, way ahead of its time. Olivia Hussey is a sorority sister, Keir Dullea is her creepy ex-boyfriend and Margot Kidder a doomed friend. Someone's calling the sorority house leaving wacked out, psychotic messages, and sisters are turning up dead. All of these ideas were ripped off heavily by later horror films, from "When a Stranger Calls" to "Scream 2" to "The House on Sorority Row."
But director Clark delivers the now-familiar theme of sorority girls in peril with more class and finesse than any of those who imitated him. The phone calls in this film are genuinely warped and terrifying—far scarier than the crank calls delivered in either of the "Scream" films. Excellent performances by veteran actors Hussey ("Romeo and Juliet") and Dullea ("2001: A Space Odyssey") add to the power of this very creepy, atmospheric film, easily one of the best slasher movies of all time. By today's standards, the story may be a little slow. Yes, the actresses don't look like they're college aged.
But all in all, this is an absolute must see and undeniably the finest Christmas fear film ever made -- way better than any of the "Silent Night Deadly Night" filmes. Clark was also behind two other classics, "Deathdream" and "Children Shouldn't Play with Dead Things."