Hey guys - I am trying to help a friend locate a book he read in the early 80’s so it was written before then. It’s a sci-fi book about a guy who has these dreams and they always have the same people in them but they are always playing a different role. In the end, it turns out that he is really the only person left on earth and the people in his dreams were really androids.the cover had an image of a body floating in space. Any help would be greatly appreciated!!!