The village postman delivers three valentine cards, each wrapped around a potholder containing a highly toxic plant; three females die as a direct result of handling the leaves. The postman is promptly detained for questioning and subsequently arrested on a murder charge. Miss Tayke disagrees with the police, advising them that the postman is only a pawn sucked in to do the poisoner’s dirty work for a pittance. With the aid of her niece, the television star Verna Day, Miss Tayke sets out to detect and expose the callous murderer by lulling him into a trap from which there is no escape…