The Time Machine
by H. G. Wells
Wells mentions time travel gently as a concept, but basically the Time Machine is about the ultimate future it sees for humanity: The nameless time traveler sets out on his way to a world that will turn 802.701 AD, and there he finds humanity divided between Eloy and the Morlocks. Eloy is a gentle, victorious, empty race that doesn't work; Morlocks, by contrast, are a barbarian race that uses Eloy for food. It's a brutal vision and it's exciting.
