Speculative fiction as a literary genre is a test of the renewed relation to nature presented as possible reality. The vision of nature presented by some science fiction and fantasy authors varies along these lines. The hypothesis underlying the present article is that these "speculative fiction-proposed natures" force us to rethink the rapport between time and space. Therefore, we need to examine to what extent science fiction and fantasy, focused on the preparation of an uncertain future, play on the links between time and nature and reconfigure both the agencies and the aesthetic situations that serve as experiments.