Episode 241- Chapter 17 and 18
Gorias is Bren’s first metropolis in Annwn. When they first arrive they encounter the Queen’s guard, who take Morias, Tadg, Fí, and Bren to the castle. There they meet the Breo-Banríon herself and her son, Ruadan.
Read more on Royal Road:
https://www.royalroad.com/fiction/88011/children-of-the-cold-moon-the-four-treasures-saga
Reader Compendium:
https://www.longwinded.one/season-5-the-children-of-the-cold-moon/