The Bad Seed takes place in a small Southern town where Colonel and Christine Penmark live with their daughter, Rhoda. On the surface, Rhoda is sweet, charming, full of old-fashioned graces, loved by her parents, admired by all her elders. But Rhoda’s mother has an uneasy feeling about her. When one of Rhoda’s schoolmates is mysteriously drowned at a picnic, Mrs. Penmark is alarmed. For the boy who was drowned was the one who had won the penmanship medal that Rhoda felt she deserved.