Slaughterhouse No. 5, or the Children's Crusade

You could say it's a story about the destruction of Dresden, but then the question remains what to do with the little green men and their home planet of Tralfamador. You could say it's pure fantasy, but it so happened that Dresden was actually destroyed during World War II, and Kurt Vonnegut was one of the few American prisoners of war who survived the bombing in February 1945. One of the most important books in world literature of the 20th century.