When Penelope goes to stay with her aunt and uncle in an ancient Derbyshire farmhouse, she is immediately drawn to the wonderful atmosphere of the place and longs to discover all the secrets of its past. Soon, Penelope finds herself slipping back in time to the sixteenth century, where she is welcomed by the Babbington family whose home it was then.

As the lines between past and present blur, Penelope becomes caught up in the tragic events that befall her new friends, as they make plans to rescue the doomed monarch, Mary Queen of Scots.