Robert A. Heinlein’s 1957 The Door into Summeris a standalone SF novel. I am glad that it had no sequels and no prequels, as I am sure I would have grown to hate them as well. Why? Read on.
It’s 1970 and Dan Davis has survived World War Three. He and his business partner have started a cutting-edge cybernetics company. The business is stolen from him by his conniving fiancée (Belle) and his equally traitorous partner (Miles). Who could have predicted that blindly signing business documents could turn out so badly?
The evil pair aren’t satisfied with bilking Dan out of his company. They want him gone; he might make trouble. Murder, they feel, is too risky. But drugging him and putting him into suspended animation … that’s different.
Dan goes to sleep in the futuristic year 1970. He wakes in the even more futuristic year 2000.