Everything from how the mysteries of the House of the Undying work to the role it plays in the story (Dany's and Euron's, mainly), including theories about what the shade trees are (related to weirwoods? something else?), where they come from, what they symbolize, what about the little dwarf, and more.

Special thanks to artist Oana Novicov for the title image and all her new HOTU art featured in the video! Really outstanding work, check out her art: https://www.deviantart.com/oananovicov712