The latest episode of 'House of the Dragon' introduces Alys Rivers. Here's why she is important and what happens to her.

• The latest episode of "House of the Dragon" introduces another key character for the upcoming civil war.
• The key character appears to be Alys Rivers, a witch who can see the future.
• Here's what to know about the character and her possible future in the series.

Warning: Spoilers ahead for "House of the Dragon" season two, episode three, and for the book "Fire and Blood."

The latest "House of the Dragon" episode may have introduced another figure who will be key in the upcoming "Dance of the Dragons" civil war.

In episode three, fan-favorite Daemon Targaryen easily takes over Harrenhal and begins to prepare the derelict castle for war.

Before going to sleep, Daemon has a hallucination involving a younger version of his niece/wife Rhaenyra Targaryen (Milly Alcock), and Jaehaerys Targaryen, a child who was murdered on Daemon's orders.

In the sequence, Rhaenyra stitches Jaehaery's head back onto his body and lectures Daemon about cleaning up her husband's mess.

Then Daemon awakes outside Harrenhal and meets a woman in black who tells him, "You will die in this place."

The woman appeared briefly earlier in the episode when Daemon first comes to Harrenhal, but she isn't formally introduced on either occasion. The actor looks like Gayle Rankin, who was cast in the series last year as Alys Rivers, a healer and resident of Harrenhal.

Alys also appeared in "Fire and Blood," George R. R. Martin's book that inspired "House of the Dragon."

The TV series, which is the prequel of the record-breaking "Game of Thrones," has built anticipation in season two by subtly introducing important book characters including Alys and bringing all the major players on board before the civil war kicks off.

Here's why Alys is an important character to watch in the upcoming episodes of House of the Dragon.

Alys becomes Aemond's lover and has his only child

In "Fire and Blood," Alys was a child nurse for the House Strong family in Harrenhal and could apparently see visions of the future.

When Aemond Targaryen, Daemon's nephew, and Ser Criston Cole take over Harrenhal in the name of Aegon II, Aemond orders the deaths of House Strong because they assisted Daemon. Aemond spares Alys' life, and she becomes his bedmate.

Later, Alys becomes pregnant and claims she is carrying Aemond's child. When Daemon returns to Harrenhal to duel with Aemond, Alys watches both men fight and die in Gods Eye lake.

She then disappears until after the civil war between the Blacks, supporting Rhaenyra's family, and the Greens, supporting Aegon's family, has ended.

At this point, she has taken over Harrenhal with a group of outlaws and claims her son is the rightful heir to the throne, challenging the current king, Aegon III. There were also rumors that she had a dragon inside the castle.

Unfortunately, her story ends there, and she isn't mentioned in the rest of "Fire and Blood."

Since "House of the Dragon" is mostly centered on the "Dance of the Dragons" civil war, we may not find out what happened to Alys and her child. But she may have a larger role in the series since she's already interacting with Daemon.