When Rosamund Tomkins enters the world she is so different, with her darkling eyes and strange laughter, that the midwives are afraid, believing her a changeling. But Rosamund's life is set to be anything but enchanted. In 1600s England, Rosamund Tompkins is the “illegitimate” daughter of a nobleman working as a servant in a country inn. Her stepfather and brothers are abusive, and she works under him at the inn. It is only when she is married off to a nobleman that her life undergoes a wondrous transformation. Clever, quick and irrepressible, Rosamund soon becomes the darling of the haut ton, and presides over her luxurious chocolate house where the rich go to be seen and indulge in their favourite pastime, drinking the sweet and heady drink to which they've become oddly addicted. But in the shadows a web of conspiracy is spinning. The return of a man from the past brings Rosamund into mortal peril and up to the brink of destruction. As she fights for her life and those she loves through the ravages of the Plague and London's Great Fire, Rosamund begins to realise she will be forced to make a choice: walk away from all she knows and has grown to love with her soul intact, or make a deal with the devil...