In 1817, two English cousins take a honeymoon "Grand Tour of the Continent" with their new husbands and become entangled in a mysterious plot to create a magical Emperor of Europe.
In 1817 in England, two young cousins, Cecilia living in the country and Kate in London, write letters to keep each other informed of their exploits, which take a sinister turn when they find themselves confronted by evil wizards.
In 1828, English cousins Cecelia and Kate and their husbands search for a missing German railway engineer and with the help of their wizardry skills, uncover a plot that could endanger the unity of England.