Through the Underworld to Zeus

I got this unsettling dream, and I don't know if I could call it a nightmare, so the following description could be my approximation. It started when I was restrained in a dark, empty library. (I think; and I don't remember whether a scary apparition appeared.) Then suddenly, I was in the presence of my parents (maybe a few other adults, maybe my Idaho relatives?). Then at one point, as I may have died and turned into a spirit, walking along other souls, we were strapped to a sort of conveyor belt that even submerged us in a tunnel full of water (I think it was to kill any apsaras or something, how disturbing...); the atmosphere there was mostly dark with a hint of dark green light. At the end of that ride and into a wide chamber, a giant figure who I think is Zeus greeted us, saying that he wanted us to work out because he wanted (physically?) strong mortals living on Earth. (Whether we were reluctant to exercise or did so, I don't remember.)