Highlights

Mysaria, known as the White Worm, is an elusive and cunning character who wields a powerful spy network in King's Landing.
Her appearance in the show is drastically different from the books, and her moniker is likely a code name to protect her identity.
Mysaria's loyalty and allegiances are complex, as she both assists and potentially betrays Daemon Targaryen, and her ultimate fate remains uncertain.

Secrets can be the currency of power — as is demonstrated by Varys and his “little birds” in Game of Thrones. There is a similar, elusive character in House of the Dragon, who employs a whisper network in King’s Landing: Mysaria (also known as the White Worm).

Portrayed by Sonoya Mizuno, Mysaria is originally a slave from Yi Ti, who is first introduced as a sex worker (in the books, she is a “dancing girl” from Lys). Although she lurks in the background during much of the first season of House of the Dragon, she emerges as the artful and duplicitous White Worm later on.

House Of The Dragon: The Most Significant Changes Made By The Showrunners

House of the Dragon is an adaptation of Fire & Blood by George R.R. Martin. However, the showrunners inevitably made several notable changes.

Why Is Mysaria Known as the White Worm?

Mysaria (the White Worm) in House of the Dragon

In the books, Mysaria is described as being quite bloated due to her age, with skin “as pale as milk”. Hence, her enemies refer to her as ‘Misery, the White Worm’. In the show, however, her appearance has been drastically changed, and her moniker seems to be just a code name to keep her identity a secret (or to commemorate her consistently white wardrobe choices).

The name is first mentioned in season 1, episode 4, “King of the Narrow Sea”, when Otto Hightower is told that “a messenger brings word from the White Worm”. Later, when Otto shares the news with King Viserys I Targaryen, he claims that his source “as yet, has never led me astray”. It is revealed that Mysaria has elevated her status from a prostitute to an information broker (“I learned that the skin trade could only take me so far in this life”). Under the alias ‘White Worm’, she now wields a lucrative network of spies in King’s Landing.

Mysaria asserts her dominance as the White Worm again later on, when she learns of Viserys’ demise (through Talya, lady-in-waiting to Alicent Hightower) before it has been publicly announced. In a struggle of power, Otto and Alicent separately send their men to find the missing Aegon II Targaryen in King’s Landing. Taking advantage of the latter’s inebriated state, Mysaria kidnaps the prince and hides him beneath an altar in the Grand Sept. She notifies Otto that she will disclose his location on the condition that the children’s fighting ring in Flea Bottom is shut down. As the White Worm boldly reminds the Hand of the King:

When […] you install your grandson on the throne, remember it was me who put him there. I could have killed him as easily as a wasp on fruit. There is no power but what the people allow you to take.

Does Mysaria Betray Daemon?

Mysaria and Daemon in House of the Dragon

According to Fire & Blood, Mysaria becomes Daemon Targaryen’s paramour when she is still a dancing girl. She even becomes pregnant with his child around 105 AC, when they are living together at Dragonstone. When Daemon gives her a dragon egg, an angry Viserys orders him to return it and send Mysaria back to Lys. On her way back, Mysaria eventually loses the child during a storm at the Narrow Sea.

During the Dance of the Dragons, Daemon seeks Mysaria’s help in taking revenge for Lucerys Velaryon’s murder. She hires two assassins, Blood and Cheese, to infiltrate the Red Keep and kill Prince Jaehaerys Targaryen. When Rhaenyra Targaryen assumes the Iron Throne, she appoints the White Worm as the unofficial mistress of whisperers. Soon after, she apparently betrays Daemon, by reporting to the queen that her husband has been sleeping with his fellow dragonrider, Nettles, in Maidenpool.

In House of the Dragon, the relationship dynamics between Mysaria and Daemon have been altered. When Viserys banishes Daemon from King’s Landing, he steals a dragon egg and falsely announces that he intends to marry Mysaria, who is now pregnant. When she discovers that Daemon has been using her lowly status to provoke Viserys, she is infuriated and leaves him:

I have been sold as property more times than I care to count, beginning in a homeland I can no longer recall. Most of my years have been spent living in terror […] I didn’t come into your service wanting gold. Or power. Or station. I came to you to be liberated [from] fear.

When she rises through the ranks as the White Worm, she seems to have conflicting feelings for Daemon. Although she is the one to send an informant to Otto with the news of Daemon and Rhaenyra’s tryst at a pleasure house, she also takes care of a drunk Daemon afterward.

What Happens to the White Worm?

In 130 AC, Mysaria warns Rhaenyra about the riots in King’s Landing, which cause her to flee from the city. Mysaria, however, remains at the Red Keep along with other members of the court. She is ultimately captured by Perkin the Flea (a hedge knight loyal to the greens), who tells her that she will be allowed to live if she manages to walk naked to the Gate of Gods while being whipped. Unfortunately, she only makes it halfway before dying.

However, the White Worm’s on-screen counterpart may have a different ending. When Larys Strong lets Alicent know that Otto has been using the web of spies for his own gain, she agrees that “it must be taken out at the head”. Later, a hooded person is seen walking away from Mysaria’s house while it is engulfed in flames. It is unclear whether this signifies the end of the White Worm, especially since there are no signs of anyone perishing in the fire. If she does survive, this event could be a turning point for the White Worm, and explain why she allies with the blacks later on.

It should be noted though that House of the Dragon has often deviated from the source material. As Mizuno states in an interview with Women's Wear Daily:

My character veers quite far away from the character in the book. That is both liberating and a challenge for me and the director. Liberating in the sense that we had more free rein, but also it still had to have a kind of framework.

House of the Dragon

House of the Dragon is HBO's prequel series to Game of Thrones. Set hundreds of years earlier, the show follows the inner machinations and rivalries of the Targaryen royal family. The show was created by Ryan Condal and George R.R. Martin, and stars Matt Smith, Emma D'Arcy, Rhys Ifans, and Olivia Cooke.