Mayhem begins with a car crash on a Los Angeles freeway. A police lieutenant (Steven Bauer) assigns one of his cops, Brandy Martinez (Melina Lizette), to go undercover. Her mission: To worm her way into the car theft syndicate that's behind the smashup. As expected, it's a dangerous course, but she manages to gain access to one of the biggest crime groups. She soon realizes, however, that there are bigger, more menacing matters at hand.