The Secret of Sybil

Sybil has spent twenty-three years watching life pass by from her family's country estate while they enjoyed all the pleasure and company available to the wealthy in 1920's America. But the day her parents and sister are due to return from an extended stay in the big city, everything Sybil has known and accepted begins to change, starting with the unexpected appearance of a handsome stranger looking for assistance.
Who is this man and what could he possibly want from Sybil?