'House of the Dragon' had a surprising cameo in the latest episode from an actor who said they wouldn't return

• There's a surprising cameo in "House of the Dragon" episode three.
• The episode sees Daemon Targaryen (Matt Smith) take control of the huge castle, Harrenhal.

Warning, spoilers ahead for "House of the Dragon" season two, episode three.

An unexpected "House of the Dragon" star just popped up for a cameo in the third episode of season two after previously saying they wouldn't come back.

The episode sees Daemon Targaryen (Matt Smith) travel to Harrenhal, north of King's Landing in Westeros in an attempt to take it as a stronghold for the Blacks.

But once he arrives, and the members of House Strong freely give it over to him, his first night is plagued by two things: A leaky roof to his bed-chamber, and a spooky vision about his life.

In his dreamlike vision, Daemon believes that an unknown person tries to break into his room. After drawing his sword and trying to find the would-be intruder in the castle, he finds a woman sitting by a fireplace.

When she turns round, it's none other than the young version of Rhaenyra Targaryen, played by Milly Alcock.

"Always coming and going, aren't you? And I have to clean up afterwards," she says while sewing Jaehaerys' head back onto his dead body.

The vision is a nod to Rhaenyra feeling used by Daemon and how she has always tried to fix the mess and destruction he leaves behind.

The metaphor here is that she's dealing with the ramifications of the season two premiere when Blood (Sam C. Wilson) and Cheese (Mark Stobbart) killed the Targaryen toddler on Daemon's orders.

It is surprising to see Alcock in the role again after she played Rhaenyra in the first half of season one, before Emma D'Arcy took over following a 10-year time jump.

In March 2023, Alcock denied rumors that she would return to "House of the Dragon," telling Deadline, "No. It's done."

Granted, Alcock's season two cameo isn't a huge moment like a dramatic battle or a grisly death scene, so it wouldn't have taken long to film.

In 2022, showrunner Ryan Condal said he wasn't sure whether she would need to return as young Rhaenyra because the story moves forward in the timeline.

"I mean, look, I don't know. [They] are not a part of the story that we're telling yet. That's not a thing that we're doing right now," he said.

After passing the character to D'Arcy in 2022, Alcock commented on her exit and what she wanted to do next, saying: "I'm not doing any fantasy roles. I don't want to do anything like that. I have done it and I don't need to do it again. I am just kind of waiting for the right project. I am not in a rush to jump on something."

As for the future, it was announced in January 2024 that Alcock will play the titular DC superhero in "Supergirl: Woman of Tomorrow," in James Gunn's rebooted DC Universe.

Gunn said he was "blown away" by the actor during her audition after seeing her in "House of the Dragon."