1.The opening credits have changed. Viserys's symbol is now filled with blood, indicating his death, and instead of following the bloodline of Rhaenyra, which the credits have previously done, we switch to Alicent and her descendants. Alicent's symbol represents House Hightower combined with the Faith of the Seven.
We see four bloodlines coming off Alicent and Viserys's union — that's right, four: Aegon II, Helaena, Aemond, and a child we haven't seen yet, Daeron.
Meanwhile, we get a close-up of the symbols for Alicent's other three children: a spider for Helaena, a naked woman lying on top of what could be a dragon egg for Aegon II, and a sapphire for Aemond.
2.You might remember from earlier in the season that Ser Harrold Westerling was Princess Rhaenyra's sworn protector when she was growing up — so it's no wonder he refused to murder her (in addition to, you know, all his vows and morals).
3.The little kids we see are Helaena and Aegon II's twins, Jaehaera and Jaehaerys.
4.Helaena repeats her "beast beneath the boards" warning in this episode, which many fans theorized was a future plot from the book but now seems likely to have been a prediction about Rhaenys bursting through the Dragonpit on her dragon, Meleys.