It tells the story of Rowan Popplewell and his sister, Nina, who, while emotionally disturbed by the death of their mother, travel back in time to the French Revolution.

The Golden Hour tells the story of Rowan and Nina's adventures the summer after their mother's death.

Thirteen-year-old Rowan's life is at an all-time low: his father has turned to drinking, the family business is becoming a financial disaster, they have had to move from their house to a small apartment, and his musically talented ten-year-old sister Nina has become withdrawn.

Rowan and Nina meet two twins, Xanthe and Xavier Alexander, who tell them about an old abandoned resort that appears to be haunted.

Nina seems interested in using the machine to escape her troubled life, especially when Rowan tells her about the Enlightenment, a period of European history when superstition and church dogma began giving way to logic and reason, art and science made tremendous strides, and truth and beauty were celebrated.