The AC comment has merit. I see the novellas "By His Bootstraps" (Anson McDonald~Robert Heinlein) and Henry Hasse's "He Who Shrank" (1936) deal with, respectively, time travel and dimensionality in original ways, not as a cheap shot but as a thoroughly thought out, mind bending, scrape the stars with your mind kind of story.
He Who Shrank was immortalized poorly in the Incredible Shrinking Man movie http://www.imdb.com/title/tt0050539/ but never approached Hasse's stunning conclusion. That is a property (in the Hollywood sense) that has never been explored.
There are a lot of concepts out there that only the imagination can create and understand, way beyond those concepts foisted upon us by Sci-Fi writers who distinctly lack imagination.