Tara's Mother is alternate-history Irish-flavoured Christian science fiction and is the third Book in the series The Throne--a history of the alternate Earth called Hibernia, or Ortho Earth as the Metans term it.

Tara's Mother is the third part of the alternate history story of two long-lived and hard-to-kill men, Samadeya-Qayin and Pelik-Qayin, the alternate continuations of the repentant and unrepentant Cain respectively, always deadly enemies, once Thor and Odin, but in the last millenium duelling over the High Kingship of Ireland.

Tara's Mother continues the story behind the history of Hibernia's fifteenth century from the perspective of five principal participants, each of whom loomed larger than life over their contemporaries--Samadeya and Pelik (the two Cains), with army officers Amethyst Meathe, Joane O'Donnell, and Thomas Rourke, who led the Irish forces at the pivital battle of Mount Sainte Jean.

Tara's Mother is the sequel to Culmanic Parts and Rae's Blood, and continues the alternate history enmity of the long-lived Samadeya-Qayin, ally of the Almighty and check against Pelik-Qayin, who is something more than evil twin.

In Rea's Blood, Amy Rea, Samadeya's adopted daughter, and First Lord of the Admiralty, was shot down aboard her flagship Victory at Trafalgar. But two powerful look-alike women do emerge from the smoke and blood--Amy's flag officer Joane O'Donnell, and the mysterious Amethyst Meathe, who both play a vital part in Thomas Rourke's battle against the French despot at Mount Sainte Jean, near Waterloo.

Joane takes on prominent military role in now allied new France. But Amethyst still has battles to fight--first with lead enemy nation Spain, then with Ireland's own King Frederick and his would-be replacements back home. She takes over from her mentor as "The Mother"--High Queen of Low Tara, queen maker for several nations, and continues Amy Rea's battle against God's enemies.

Tara's Mother relates the rest of the story of Ireland's fifteenth century war with Spain and France, narrating never-before-known details of the king making undertaken by one of the leading characters. It also reveals the "secret of the ages" that the Paladins of that day and subsequent times faithfully kept until Lord Lucas discovered how to decrypt Amethyst Meathe's journals.

The history of Ireland's throne will pick up in 1492 in the subsequent novel Book 4 of The Throne, titled Paladin, which also serves as the seventh Book of Rick's other series, The Interregnum.

Events of Tara's Mother play out on Hibernia, in the Royal Army Naval Corps (RANC) in Spanish Waters, at Mount Sainte Jean, on a mad dash from Waterford to Tara, and in the 1941 uprising at Tara.