Plot

Ellen Carson, a busy real estate agent, makes a split-second decision to change lanes, inadvertently cutting off a delivery truck driver named Eddie Madden. Unbeknownst to her, Eddie is deeply troubled and retaliates by pursuing Ellen relentlessly on the freeway. After reporting him, which costs Eddie his job, he becomes dangerously obsessed with Ellen and her teenage stepdaughter, Cynthia. Haunted by his own tragic past, he devises a sinister plan to eliminate Jim, Ellen’s husband and Cynthia’s father, hoping to take their place as a new family.