An Imperial order forces the Atreides family to leave their own green planet Caladan, and move their life to the most hostile habited planet in the Empire: the desert-planet Arrakis, better known as Dune.  All of that thousands of years from now.
Dune is just a pile of sand, drier than Earthly humans can possibly imagine, but it also contains the most valued substance in the Universe: spice, a rare matter that is indispensable for the functioning of this Empire.  Without the paranormal trance evoked by this spice, the helmsman of the starships wouldn't be able to steer their way in between stars and planets at the speed of light, and without the very same spice the Noble Families would have to be satisfied with a life of normal length.

Needless to say that every means, political, military, or whatever other is applied to have or keep control over the planet, and thus over the trade.  It is in this cobweb of intrigues that a young Paul Atreides finds himself almost alone on this extremely hostile planet, and needs to hide in the desert to retain the planet for his family.
The planet is natively inhabited by the Fremans, a desert people that has adapted as much as humanly possible to this climate.  Paul wants them to be his allies, but it takes him earning their respect before they embrace him as one of them.  And that is bad news for his enemies, because there is no more hardened army than the Fremens.

I just borrowed "a" science-fiction story from the library.  Well, this is by far superior to most of the starship-lasergun-strange beings kind of stories that most science-fiction unfortunately is.  In fact this book is several in one.  One can read the political struggle, the religious scheming, even a philosophical essay about human interactions.  And of course there is the plain adventure-novel.  Dune is great, it's impressive, as impressive as the worms.  Don't think like I did, and that the translator made a mistake ;-)  They really are that huge.

What I like about this story, is in fact the same as what I like about Lord of the Rings, or Stephen King's fantasy: it fits.  It is possible.  There is no need for a sudden spell nobody ever heard of, or a magician that fixes everything.  And most of all: the story is so strong, it can survive being ported to any surrounding.  It doesn't rely on anything specific from the future, the story stands on itself.  And that is rare.