Robert A. Heinlein is widely and justly regarded as the greatest practitioner of the art of science fiction who has ever lived. Here are two of his greatest short novels:

GULF: In which the greatest superspy of them all is revealed as the leader of a league of supermen and women who can't quite decide what to do with the rest of us....

LOST LEGACY: In which it is proved that we are all members of that league -- or would be, if we but had eyes to see....

PLUS TWO GREAT STORIES: Two of the Master's finest: one on the nature of Being, the other on what it means to be a Man.