So much went down during the House of the Dragon season 3 finale, "The Treasons at Tumbleton," that the fate of the Mistress of Whisperers, Lady Mysaria (Sonoya Mizuno), feels somewhat swept under the rug in comparison.
After failing to inform Queen Rhaenyra Targaryen (Emma D'Arcy) about her half-brother Aegon's (Tom Glynn-Carney) reunion with his dragon Sunfyre, who was previously thought to have perished during the Battle at Rook's Rest, Rhaenyra fires Mysaria from her small council position without warning and arranges for her passage out of Westeros. In addition to ending their professional association, this also presumably ends the romantic relationship between Rhaenyra and Mysaria.
This scene feels eerily similar to a plot point from House of the Dragon's predecessor, Game of Thrones. That story ends in a heartbreaking tragedy, which does not bode well for Rhaenyra and Mysaria in the forthcoming fourth and final season of House of the Dragon.

Tyrion and Shae, a love story gone wrong
While serving as acting Hand of the King in Game of Thrones, Tyrion Lannister (Peter Dinklage) keeps Shae (Sibel Kekilli), a foreign-born prostitute with whom he's fallen in love, nearby in King's Landing, so that the two can continue their relationship in secret. However, this setup proves to be too dangerous. Tyrion's family comes too close to comfort to discovering Shae, with his sister, Cersei (Lena Headey), threatening Ros (Esmé Bianco), a different prostitute, thinking she is Tyrion's lover, and his father, Tywin (Charles Dance), promising to kill the next woman he catches in Tyrion's bed.
Despite Tyrion's insistence that Shae depart King's Landing for her own safety, she refuses to leave his side. Finally, Tyrion dumps Shae, pretending to never have loved her, so she'll not want to remain with him, instead leaving for Pentos. However, this backfires, and Shae remains in King's Landing long enough to testify against Tyrion in his trial for killing King Joffrey Baratheon (Jack Gleeson), a crime for which the audience knows Tyrion is innocent.
The mere sight of Shae at the trial sets Tyrion off, and she makes things worse by lying about his guilt. This ruins the contingency plan Tyrion's brother Jaime (Nikolaj Coster-Waldau) had set up, which would result in his joining the Night's Watch.
After Tyrion's trial goes awry, Jaime helps him escape his captivity, and Varys (Conleth Hill) arranges for his passage to Essos. However, on his way out of the Red Keep, Tyrion stops by his father's chambers, where he discovers that Tywin has slept with Shae. Enraged to see each other, Tyrion and Shae physically fight, resulting in her death. This causes Tyrion to kill his father on his way out of Westeros.
Thanks to a simple misunderstanding, Tyrion's true love became his greatest enemy. All he wanted was to keep her safe, and a result, she would end up dying by his own hand.

Could Mysaria become House of the Dragon's Shae?
Rhaenyra's firing of Mysaria feels similar to Tyrion's break up from Shae, simply in that both feel abrupt for Mysaria/Shae, and Tyrion/Rhaenyra arrange transportation out of Westeros, implying they hope to never see their former lover again. Much like Shae, Mysaria does not seem to be taking this dismissal well. In her last scene of the season, Mysaria is show watching Rhaenyra's big speech, proving that she does not, in fact, leave King's Landing after her firing, and her look conveys anger and resentment towards Rhaenyra.
In House of the Dragon's source material, George R.R. Martin's Fire & Blood, Mysaria never betrays Team Black, remaining fiercely loyal to Daemon (Matt Smith), her first lover in the series, up until her death. However, the character of Mysaria has already been greatly changed, with her romance with Rhaenyra, a defining storyline for her, an invention of the show.
As such, this opens the door for a potential betrayal on her part. Mysaria clearly does not take well to being fired and dumped in one fell swoop, and her remaining in King's Landing sets up more story potential for the character next season.
Could she follow in Shae's footsteps, betraying her former lover after a brutal breakup? Having served as Master of Whisperers until recently, still controls a vast spy network. Could she turn them against Team Black, potentially helping Team Green, just to get back at Rhaenyra? Assuming House of the Dragon features the same ending for the Dance as the book, then Rhaenyra's downfall in season 4 is all but guaranteed. If Mysaria is meant to evoke Shae in the season 3 finale, could she play a part in the fall of Rhaenyra?
You can stream all three seasons of House of the Dragon on HBO Max. The fourth and final season is expected out in 2028.
