House of the Dragon Season 3 just rewrote the rulebook, and book readers are not ready for what changed. Martin’s Fire & Blood in major ways across its third season, altering key character arcs, battles, and prophecies ahead of the final season. House of the Dragon Season 3 has completely altered the source materialHouse of the Dragon season 3 introduced entirely new storylines while removing key book characters from George R.R. Aegon and Aemond’s Invented ReunionIn Fire & Blood, Aemond never attempts to kill Aegon, and the two brothers never reunite after Rook’s Rest. Season 4 must now reconcile these sweeping changes with the book’s predetermined fates for Aegon, Aemond, and Rhaenyra.