The Timestream is at least six known versions of Planet Earth arranged in hexagonal fashion. Each has different histories and societies, some different geologies, but all share the same physical laws and chronology. At critical historical points on one of the planets, crucial decisions result in two Earths with the same prior history but differing subsequent ones. Major events on neighbouring planets in the Timestream affect each other strongly...
In the decades following the deposition of James IV, High King of Ireland and the worlds he rules, his descendants and relatives continue their struggle to survive clan MacCarthy's genocidal high-tech schemes plots. Katherina Rourke loses everything except her close-knit group of friends when first her mother and then her father are murdered. Sean Reilly, the man she once loved but now hates, and his allies seek to depose a corrupt donal.
Katherina's daughter comes of age as she builds The Friends of the Day dedicated to restoring Tara's true throne. While Katherina's friendships disintegrate around her, a subsequent ruler uses Sean in an attempt to kill Katherina, Jack, and their infant Mara. Will he succeed?