Grade-schooler Rhoda Penmark (Patty McCormack) is sweet, smart … and inherently evil! After a school chum dies during a picnic, no one suspects Rhoda, except the janitor (Henry Jones) of her apartment building. But when Rhoda's mother, Christine (Nancy Kelly), finds out that her own mother is a cold-blooded killer, she begins to suspect Rhoda might be the victim of some faulty genetic wiring. Based on Maxwell Anderson's play.