House of the Dragon's season three finale has made changes that suggest showrunners Ryan Condal and Sara Hess may be rewriting one of the most tragic character arcs from George R.R. Martin's source material, Fire & Blood. Rhaenyra Targaryen, played by Emma D'Arcy, is shown reaching a point of no return after losing her sons and key allies, prompting concern among fans about how far the planned fourth and final season will diverge from the book's original, harrowing conclusion for her character.

In the book, Rhaenyra's brief and brutal rule over King's Landing earns her the nicknames "Maegor with Teats" and "Rhaenyra the Cruel" after the smallfolk blame her for her half-sister Helaena's suicide and heavy wartime taxation, while a string of betrayals — including dragonriders Ulf and Hugh switching sides at the Battle of Tumbleton — leaves her isolated and easily captured by her rival, Aegon Targaryen. The show has already diverged notably, including depicting Rhaenyra force-feeding and effectively causing Helaena's death directly, and merging the book character Nettles into Rhaena Targaryen, changes that could significantly alter how her downfall unfolds on screen.