Nancy takes up residence on an old clipper to find a clue to its missing figurehead. She is confronted with fire, theft, and other dangerous situations.
Despite warnings from a stranger, Nancy sets out for France to search for a flight of 99 steps which may help solve the mystery of a weird dream and a possible case of blackmail.
After a near disaster, when the boat Nancy and her two friends were in gets caught in a horrible storm, a mystery unravels in a bungalow that they have found.