2001: A Space Odyssey by Arthur C. Clarke
On the plains of Africa a tribe of ape-men on the verge of extinction encounter a strange rock, a carved and polished monolith that awakens in them the spark that will one-day move them forward into civilization.
Millions of years later, Dr. Heywood Floyd travels to the moon to investigate reports of a strange object found buried in the Tycho Crater; an object that, according to scientific tests, predates the rise of human civilization on earth.
In the furthest reaches on the Solar System astronauts David Bowman and Francis Poole command the Discovery One, a spaceship originally intended to travel to Jupiter that is suddenly given the mission to be the first manned flight to reach Saturn.
What are these mysterious monoliths, where have they come from, and why have they suddenly appeared at such momentous points in the history of the human race? What awaits the Discovery One at Saturn? What does this mean for the future of the human race? Have we finally found the answer to the question we have been asking for over a century, are we alone in the Universe? Or are there intelligent civilizations in the farthest reaches of Space?