You can watch the official trailer for Game of Thrones Season 8 Episode 3 above.
The second episode of Game of Thrones’ eighth and final season, “A Knight of the Seven Kingdoms,” included an Easter Egg from Podrick (Brienne’s squire). He sang a song known as ‘Jenny’s Song’ which comes from George R. R. Martin’s A Song of Ice and Fire novels. The song tells a tale of a
woman named Jenny of Oldstones and her prince, Duncan Targaryen, who was Daenerys Targaryen’s great uncle. Duncan gave up the Iron Throne for love. This is a fitting foreshadow for Daenerys’ relationship with John Snow. Who will give up the Iron Throne? That is, if they even have the chance to rule by the end of the series. One thing is for certain, the Night King and his army have arrived at Winterfell.