Season 5 of Stranger Things hinted at a tragic backstory for Vecna involving a traumatic experience in a cave - but what has already been revealed in the show's offscreen play? The final season, which premiered part 1 on Wednesday, November 26, brought back Max (Sadie Sink) while showing her stuck in a locked part of the Upside Down. She tried to escape but Vecna a.k.a Henry (Jamie Campbell Bower) chased her down - until she reached a cave. The location was part of a memory manifested by Vecna and recreated in the Upside Down.