In late seventeenth-century England, eleven-year-old Digory, forced to leave his hometown after his father is lost at sea, becomes an apprentice to the architect Henry Winstanley, who built a lighthouse on the treacherous Eddystone Reef -- the very rocks that sank Digory's grandfather's ship years before.

In 1688, the birth of a Prince of Wales ignited a family quarrel and a revolution. James II's drive towards Catholicism had alienated the nation and his two staunchly Protestant daughters by his first marriage, Mary and Anne. They are the 'ungrateful daughters' who usurped their father's crown and stole their brother's birthright. Seven prominent men sent an invitation to William of Orange, James' nephew and son-in-law to intervene in English affairs....