Warning! This article contains spoilers for House of the Dragon season 3, episode 1.
There's no turning back now: Alicent Hightower is a different character in House of the Dragon than she is in George R.R. Martin's source material, Fire & Blood. After a slow, exposition-heavy second season, House of the Dragon season 3, episode 1, "Salt and Sea, Fire and Blood," throws the show into high gear, as the bloody and vicious Battle of the Gullett takes lives on both sides of the conflict.
While the episode opens with Rhaenyra Targaryen giddy about the prospect of taking King's Landing after her secret meeting with Alicent in House of the Dragon season 2, things will have changed now that she's lost another one of her children. Safe from the devastation of the battle is Alicent, who, after promising Rhaenyra that she would open the gates of the Red Keep, is forced to manipulate her sadistic son, Aemond One-Eye, into leaving King's Landing and flying to Harrenhal (where a surprise trap awaits him).
Fire & Blood, the book on which House of the Dragon is based, isn't a straightforward chronicling of the Targaryen civil war. It's a manuscript detailing the Targaryen dynasty's history, written by an unreliable narrator and based on other people's accounts. As such, the show has taken liberty with Alicent's characterization, though betraying the Greens outright is a major deviation from her book counterpart.
In the book, Rhaenyra, her dragons, and Corlys Velaryon's fleet arrive at King's Landing, and it's a simple enough move for the Dragon Queen to take her rightful place on the Iron Throne. Aemond, Ser Criston Cole, and the Greens' forces are on their way to the Riverlands, leaving the Red Keep undefended. The Blacks do not need Alicent's help, and there's never any mention of her offering it. In fact, Fire & Blood suggests that she calls for aid against Rhaenyra when they invade the city.
In House of the Dragon season 3, episode 1, Alicent sends a forged note to her cousin, Lord Ormund Hightower, and tricks Aemond into going to Harrenhal. She's now actively involved in the Blacks' campaign, with little regard for the lives of her children, save Helaena and her granddaughter Jaehaera, whose lives she bargains for when she makes the deal with Rhaenyra. This isn't a minor narrative change. It will have a lasting impact on the story moving forward.
In Fire & Blood, once Rhaenyra has taken hold of King's Landing, she decides to spare Alicent's life. Their relationship in the show gives much more weight to this decision. It frames them as two sides of the same coin, young women forced to turn on each other under men's rule. This is arguably more interesting than Alicent being a wicked, ruthless stepmother. Where the show goes from here will be more complicated, however.
In the book, by the end, Alicent is held captive, forced to live out the rest of her days in relative isolation and grieving the deaths of her children. Her misery is torturous, a fitting punishment for her role in the Targaryen civil war. This ending now makes much less sense in the show.
While there's a chance Alicent's plans in House of the Dragon could still go wrong, leaving Rhaenyra to feel betrayed, she's clearly tried to make amends for her actions. The show implies that the Dance of the Dragons was the result of a disastrous yet relatively innocent misunderstanding rather than Alicent's own greed. Her captivity would feel much less satisfying.
Famously, after House of the Dragon season 2 ended, George R.R. Martin publicly criticized the show's handling of the story. While his most direct complaints dealt with the horrific "Blood and Cheese" incident, in which two assassins hired by Daemon kill one of Aegon and Halaena's two children, he described each change in House of the Dragon as having a "butterfly effect" on the overall story. Even the most minor changes can alter the trajectory of the war. Alicent's new role in the conflict isn't just a small character detail. It upends the entire Blacks-versus-Greens dynamic and her maternal relationships with Aegon and Aemond.
It makes sense that the writers would want to expand Alicent's story in House of the Dragon. The Game of Thrones franchise is all about examining ethics and challenging the audience's perception of right and wrong, and Alicent's characterization in House of the Dragon epitomizes that. Still, whether House of the Dragon will manage to stick the landing for Alicent's story in seasons 3 and 4 remains to be seen.
New episodes of House of the Dragon season 3 premiere weekly on Sundays on HBO and HBO Max.
