House of the Dragon has already deviated from George R.R. Martin's Fire & Blood by leaving King Aegon II's dragon, Sunfyre, alive rather than dead, opening up the possibility that Queen Rhaenyra Targaryen's fate could also diverge from the book. In the novel, Rhaenyra flees to Dragonstone after her rule collapses, only for Aegon to have her devoured by Sunfyre following a coup and a final conversation between the siblings, a fate corroborated within the wider Game of Thrones universe by Joffrey Baratheon's retelling in an earlier series. Because the show has reshaped the build-up to this moment, viewers can no longer assume the ending will play out exactly as written.

Key changes so far include a different explanation for the unrest that drives Rhaenyra from King's Landing, and Sunfyre surviving his injuries from the Battle of Rook's Rest rather than dying as had been implied. Aegon is currently at Harrenhal with Aemond Targaryen and Alys Rivers rather than already in hiding at Dragonstone, meaning the timeline before any final confrontation with Rhaenyra has been stretched. The article speculates this could still lead to the same outcome from Fire & Blood, or that showrunner Ryan Condal may be planning a different resolution altogether, noting that the son who witnesses Rhaenyra's death in the books is actually her child with Daemon Targaryen, also named Aegon.