Prodded by a childhood haunting, an ostensible descendant of KING ROBERT I, the Bruce of Scotland, takes a side road to his mother's family burial ground at the Dunfermline Abbey in Scotland to pay homage. Enlightenment prompts him to join in the seven-century-old debate over the proximity of his progenitor, Sir Thomas de Bruys, to the King.
Near the end of the eighteenth dynasty in Egypt, a bold daughter of a heretic Pharaoh flees after turning an infant-THE SENTINEL, to stone, using powers inherited from an Egyptian goddess. Millennia later in 1306, where the hills reply to the cries of the lost hunter's horn, thirty-two-year-old ROBERT seizes the throne of Scotland by an act of sacrilege-enabled by his Church, a black knight, and the Countess who crowned him. His twenty-two-year-old wife and QUEEN, Elizabeth de Burgh, confronts rivalry with the Countess while fearing destruction by her father's best friend-the mercurial Edward I (Longshanks), King of England. While shepherding her seven-year old stepdaughter, MARJORIE, to safety after ROBERT flees, she calls out for the SENTINEL of pharaoh's daughter to rescue them but fails. Excommunicated and imprisoned, the deprived QUEEN falls to starvation and delirium, but rescued by a manipulative man from Jerusalem-her jailor-he dumps an infant onto her lap, as hers. Fearing the child is the SENTINEL, or ROBERT's son by the Countess, she names him THOMAS.
Over seven years of confinement, from a decrepit Manor House in Yorkshire, England to the grandeur of Windsor Castle, THOMAS grows to genius while keeping the QUEEN intact as she drifts between alternate realities and plays mind games with her jailor about her plight. In the meanwhile, MARJORIE toils in a separate prison and is threatened by evil forces that followed pharaoh's daughter out of Egypt. While ROBERT and his black knight crush the English army, MARJORIE reunites with the QUEEN, but remains damaged from harsh confinement. THOMAS guides her to the light, enabling her to unleash the powers she'd inherited from pharaoh's daughter.
Victory in 1314 reunites ROBERT with his QUEEN and MARJORIE, but THOMAS'S introduction to him rejected; the King presses the Countess for the truth about him. Reconciliation and absolution follow heartbreaking loss and THOMAS begins a new life with a new title and a new Marjorie.