"When a Stranger Calls" is a frightening 40-minute premise stretched into a 97-minute movie.

Director Fred Walton sets the audience up early for a 20-minute reign of terror and gracefully shocks them out of their seats in a final blitz. But he packs the middle with drawn-out dialogue and mindless series of chases and escapes that do little more tan pad the feature film into feature length.

Carol Kane is Jill, an impish teenager babysitter who arrives at her job long after the children are asleep. She barely has time to bid hello to the parents -- a kind young doctor and his wife -- before they're off for a night on the town. Kane settles in for a long evening of schoolbooks.

Her study is interrupted by a string of unsettling phone calls." "Have you checked the children?" the raspish male voice queries. Kane tolerates four or five of these interruptions before calling the police.

Sergeant Sacker assures her that these things happen all the time. Get a whistle, he says, and the next time he calls blow into the speakerpiece. She never gets the whistle but she does get more calls. Back to Sacker who again reassures her, but puts a trace on the call.

The next call is longer and more threatening. "I want your blood all over me," the caller avers. She hangs up in terror. The instrument rings again.

"Jill, this is Sergeant Sacker. The calls are coming from inside the house."

She flees to the front door. The shadow of an intruder appears at the top of the stairs. She bursts out of the house into the arms of burly Charles Durning. Luckily, Durning is not the maniac but an ambulatory Ironsides who was the first cop to arrive on the scene.

The maniac is English actor Tony Beckley, who is still upstairs, covered who is still upstairs, covered with the blood of the two children he had torn limb from limb.

The tension of the first 20 minutes promises much. Kane is exquisite as the terrified teen. Walton makes good use of the sights and sounds of a modern house -- the automatic ice cube-maker and the telephone -- to add to the terror that climaxes with Kane's headlong rush out of the house.

Then the film bogs down. Seven years later, and the killer escapes from a mental institution; he's repeatly rejected by an aging rummy (Colleen Dewhurst). To add to his problems, he's pursued by Durning, now a private eye hired by the childrens' father and still obsessed with the case.

Beckley flips out again. The production picks up again when he spies a newspaper picture of Kane -- herself now the mother of two. She and husband set off for a restaurant leaving the kids home with a sitter.

Beckley calls Kane at the eatery to ask if she's "checked the children." Kane and spouse rush home, to discover the children are safe for the moment.

"When a Stranger Calls" ends with as suspenseful and churning a 20 minutes as it began. Beckley stalks Kane, her unbelieving husband and children. Never mind that the director never explains how the maniac found the couple at the restaurant.

When a stranger calls -- Arlington, Jefferson, Landover Mall, Marlow, Marumsco, Riverdale Plaza, Roth's Montgomery, Roth's Silver Spring West, Springfield Cinema, Tenley Circle, Tyson's Twin and White Flint.