When a raging fire destroys the modern mansion of wealthy restauranteur Joseph Skane and kills his disabled wife, Mrs. Skane's nurse, Maria, is arrested for arson and murder. Soon afterward, a mysterious caller hired investigator Anna Peters to help with Maria's defense. Although Anna has had her share of unusual cases, this one is her biggest challenge yet. Maria has refused to speak since running from the burning house, and even when she agrees to respond to Anna's questions in writing, Anna suspects she's hiding information that could clear her name...