Catherine Montour and her brother, Lionel Esmond, are separated at childhood. Catherine then goes to England where she becomes mistress to George III. Aspiring to become queen of America, Catherine enlists George in her cause. When the colonies go to war with England, Paul Revere announces the arrival of the British, colonists and British troops exchange fire at the Battle of Lexington, and the Declaration of Independence is signed. The winter at Valley Forge, the Cherry Valley massacre and the surrender of Cornwallis occur, during which Catherine and her brother fall in love with each other. They are about to be married when they learn that they are siblings. Catherine, her ambitions crushed, attempts to return to the king's grace but fails.