House of the Dragon episode 4 sets up a particularly disturbing storyline from George R.R. Martin's Fire and Blood book. The episode focuses on the return of Daemon Targaryen to King's Landing, along with Otto Hightower's plotting, and the search for a suitable husband for Rhaenyra Targaryen.
Before you read on, though, you should be warned that we'll be going into major show and book spoilers, so turn back now if you don't want to know where House of the Dragon might be headed!
Still here? Then let's get into the spoilers. In episode 4, Daemon invites his niece out to King's Landing after dark, both of them disguised as commoners. To sneak out of the Red Keep, though, Rhaenyra needs to use a secret passageway that she had no idea existed – Daemon draws her a diagram to reveal its location. The hidden passage leads all the way to the outside of the Red Keep, and from there, the duo head down to the streets.
But, as one Redditor (opens in new tab) points out, this scene could be setting up a major event from Fire and Blood: Blood and Cheese. That storyline sees a rat catcher known only as Cheese team up with a butcher using the name Blood. Together, on the orders of Mysaria, who herself is working for Daemon, they sneak into the Red Keep via a secret passageway which leads them to Alicent Hightower's bedroom. There, they tie up Alicent and await the arrival of her daughter Helaena, who has only just been born in the show (see a picture of her above). Helaena is married to her brother Aegon – the toddler seen in House of the Dragon episode 2 – and together they have two sons, the youngest named Maelor and the oldest (and heir to the throne) named Jaehaerys, along with a daughter.
This is where the story takes a terrifying turn. Rhaenyra has children herself at this point in the timeline, and one of them, Lucerys Velaryon, is killed by Aemond Targaryen – Aegon's brother – during the Targaryen civil war. As revenge, Daemon hires Blood and Cheese through Mysaria for their gruesome task.
When Helaena arrives to the room with her children, they are trapped, and Cheese tells Helaena she must choose a son to die. Eventually, after some terrible threats have been issued about what will happen should she not pick a son, Helaena chooses the very young Maelor. But Blood beheads Jaehaerys, the oldest son and heir, instead. Blood and Cheese then escape King's Landing with Jaehaerys' head, and while Cheese vanishes without a trace, Blood is ultimately caught as he tries to deliver the grisly proof of death to Daemon.
Considering House of the Dragon episode 4 revealed Daemon to have knowledge of the secret passageway, it would seem this is foreshadowing for the horrible events to come – and, as another Redditor (opens in new tab) notes, we do see rats as Rhaenyra heads out of the castle… and that seems too reminiscent of Cheese the rat catcher to be a simple coincidence.
This isn't the only bloody plot point teased in the episode, either. A blink-and-you'll-miss-it moment hints at the dark fate awaiting another major character, which you can read about through the link.
To find out when the next installment drops in your time zone, check out our guide to the House of the Dragon release schedule.