The Invisible Intruder

Nancy and her friends are invited by Helen and Jim Archer to join a ghost-hunting trip with them and three other married couples. The group investigates five haunted locations. The first one has a self-propelling canoe appearing on a lake. The next concerns a fortuneteller's prophecy hut; people hear thunder during séances but storms are not present. A phantom horse appears with its ghost rider chasing it at the third location. The fourth site is an old fort; people report seeing the ghosts of prisoners. The final investigation is at the home of a skull and shell collector regularly visited by an "invisible intruder!" This book is the original text. A revised text does not exist.