Penelope arrives from London to stay with her uncle and aunt in their farmhouse in Derbyshire. It was once the home of an Elizabethan family-and when strange things start happening Penelope begins to think they may still be there.
Penelope causes a sensation when, with her modern clothes and short hair, she steps back in time to meet the Babington family in the days of Mary, Queen of Scots.
During the church service, Penelope drops her collection money and finds something lost long ago which links her once again with the Elizabethan Babingtons.
Penelope moves in and out of the past and is deeply involved with the Babingtons and their troubles, but now Arabella Babington is becoming suspicious and threatens her life.
The plot to save the Queen of Scots is in jeopardy. Penelope is desperate at the thought of leaving Thackers without knowing the fate of the Babingtons.