NEW YEAR'S EVIL

One New Year's Eve, popular punk rock/new wave DJ Diane Sullivan (known as "Blaze" among her fans) is hosting a late-night countdown celebration, televised live from a Hollywood hotel and simulcast on local radio. All is going well until Diane receives a phone call from an odd-sounding stranger, who claims his name is Evil. He announces his intention to murder one "naughty girl" at the stroke of midnight in each US time zone; he warns that Diane, located in the Pacific Time Zone, will be the last victim. Meanwhile, Diane's son Derek arrives at the studio, but is mostly ignored by his mother; he begins behaving erratically throughout the night as he watches the show on television.

The studio crew takes safety measures and heightens security, but a string of murders begins to occur across Los Angeles; a nurse at a sanitarium is found dead shortly after midnight strikes in the Eastern Time Zone, and two women are found dead near a liquor store after midnight in the Central Time Zone. The killer uses a radio/cassette recorder to tape the sounds of his victims as he murders them and calls back the station each time, replaying the tapes over the phone to prove that he is serious.

While the killer searches for a victim to kill for the stroke of midnight in the Mountain Time Zone, he inadvertently angers a gang of bikers, who chase him into a drive-in theater. He murders one of the bikers, steals a couple's car to avoid being recognized, and drives off with the girl still in the backseat, intending to make her his next victim, but she manages to escape.

Eventually, the killer manages to sneak into the hotel, which by now has been locked down by the police. It is revealed that the killer is Diane's husband, Richard, who was previously thought to be too busy to attend. After knocking Diane out, he castigates her over her treatment of their son, perceiving her and other women's treatment of him as a slight on his character. Richard tells his wife that he hates women. He reveals his intention to kill her by chaining her to an elevator and forcing it to ride "all the way up, then all the way down," having hacked the elevator controls. While he is doing this, the police, who have been alerted to his presence, locate him. A brief firefight ensues and the elevator controls are damaged, stopping the elevator and saving Diane. Richard flees to the rooftop, putting on the mask he had used to conceal himself while entering the building. Cornered by the police, he proceeds to jump to his death; a devastated Derek weeps over his body.

The injured Diane is loaded into an ambulance, but Derek is revealed to be the driver, having taken his dead father's mask and murdered the real driver. The ambulance drives off, leaving Diane's fate unknown, as a radio announcer in Honolulu is heard announcing the stroke of midnight in the Hawaii–Aleutian Time Zone.

Richard, revealed as the killer and Diane's husband, is cornered by police after attempting to murder Diane and jumps to his death. Diane, injured, is placed in an ambulance, but her son Derek—now wearing the killer's mask—murders the driver and drives her away, leaving her fate unknown.

The climax shifts the threat from the original killer, Richard, to his disturbed son Derek, suggesting a cycle of violence and unresolved trauma within the family. Diane's ambiguous fate in the ambulance, coupled with Derek's chilling transformation, leaves the story open-ended and underscores the film's bleak take on holiday horror.