It's the first comet to buzz the planet in 65 million years, and everyone seems to be celebrating its imminent arrival. Everyone, that is, except Regina Belmont (Catherine Mary Stewart, The Last Starfighter) and her younger sister Samantha (Kelli Maroney, Chopping Mall), two Valley Girls who care more about fashion trends than the celestial phenomenon. But upon daybreak, when the girls discover that they're the only residents of Los Angeles whom the comet hasn't vaporized or turned into a zombie, they do what all good Valley Girls do…hey go shopping! But when their day of malling threatens to become a day of mauling, these gals flee with killer zombies and blood-seeking scientists in hot pursuit!