With the sometimes reluctant help of her friend Louise Sidell, Penny Parker discovers the secret behind Melvin Osandra's seance establishment, and in turn, helps her friend Nellie Marble out of her difficulties with her doll shop. Additionally, Penny is able to free actress Helene Harmon from the plague of the witch doll that will not disappear. After solving her mysteries, Penny gets the honor of writing up the story for her father's newspaper.