Nancy’s father, Carson Drew, enlists her help in tracking down a missing heiress.
While investigating, Nancy, Bess, and George stumble upon a mysterious moss-covered mansion.
The girls learn someone was murdered near the mansion and they hear strange noises coming from inside the building.
Action bounds in this thrilling adventure involving gypsies, a missing heiress, a needy elderly lady, a reclusive artist, an airplane accident, and a forest fire.