Examples of plot twists in science fiction films?

The reference supplied is a general overview of the science fiction genre, describing its themes and evolution over time. It does not enumerate particular films, plot twists, or narrative devices. Consequently, no concrete examples of plot twists in science fiction movies can be cited from the evidence. This lack of detail means that any discussion of specific twists would be speculative and unsupported by the source. Therefore, based solely on the verified information, we cannot provide examples of plot twists in science fiction films.