The “Jewels” are two severely contrasting sisters, Topaz and Amethyst Plantagenet. They are descendants of Richard III, who lost his life and kingdom to Henry Tudor, future father of Henry VIII.
Topaz always felt she was the rightful queen, and would have been, had her father been crowned as Richard’s heir. But her father was executed as a young man, and the girls never got to know him. Topaz is very bitter about their father’s wasted life, and vows to get revenge and recapture the crown.
Amethyst and King Henry begin a passionate and enduring romance that survives his divorce from Catherine of Aragon through his marriage to the doomed Anne Boleyn and up to the death of his beloved third wife, Jane Seymour, his unconsummated marriage to Anne of Cleves, his marriage to the young and spirited Catherine Howard, which also ends in her execution, and his final union with Kate Parr, who outlives him. Amethyst remains a faithful supporter, confidante, lover, and friend, through Henry’s tragic marriages and England’s break with Rome.
Until the night King Henry dies in her arms, she is torn between her love for him and for her sister. Topaz is furious at Amethyst for entering a liaison with the man whose father killed theirs. This creates a painful rift between the sisters that remains unresolved until the story's end. While Amethyst lives a comfortable but troublesome life at court as the king’s mistress, despised by some and revered by others, the determined and ambitious Topaz has her own agenda. She goes into battle with King Henry VIII, who is forced to defend his crown, and throws Topaz into prison for treason. Amethyst begs the king to release her, but he dies while she’s still imprisoned.
The stormy conflict between the sisters resolves in the end. Topaz is finally set free by Henry’s heir, the boy king, Edward VI. King Edward banishes Topaz to the New World and she embarks on a voyage with explorer Sebastian Cabot, hoping to colonize her own democratic and monarch-free realm, in what will someday be New England.