Game of Thrones season 8: Daenerys Targaryen’s downfall sealed in season 7 Missandei clue?

GAME OF THRONES season eight will see Daenerys Targaryen and Jon Snow take on the Night King with their combined forces. It’s not known if either will survive the army of the dead’s attack, however, the Mother of Dragons could be taken down by someone much closer to her - Missandei.