After an American family moves to an old country manor in rural England, one of the daughters is tormented by the spirit of the owner's long lost daughter, who mysteriously disappeared 30 years ago during a solar eclipse.

Mrs. Aylwood is a distraught mother since her daughter, Karen, vanished in the English countryside over 20 years ago. When the Carstairs family move into the Aylwood manor for the summer, strange occurrences begin to unnerve the family and Jan begins to suspect that they are linked to Karen's disappearance. As Jan unravels the dark past hidden by the townspeople, she delves further into the mystery and deeper into danger, but now it might be too late to escape the Watcher in the Woods.