Two Girls Trapped in Their Own Case picks up where Two Girls and a Dead Case left off. Sarah and Monica, best friends since high school have opened a detective agency in their small and seemingly boring town. They are given a mysterious case involving a missing girl that turns out to be a possible serial killer. When they stumble on a clue that could break the case wide open they impulsively take off and end up facing their biggest challenge ever- facing down and escaping the very killer that they are tracking.