Robert Heinlein's Hugo Award-winning all-time masterpiece, the brilliant novel that grew from a cult favorite to a bestseller to a science fiction classic. Raised by Martians on Mars, Valentine Michael Smith is a human who has never seen another member of his species. Sent to Earth, he is a stranger who must learn what it is to be a man. But his own beliefs and his powers far exceed the limits of humankind, and as he teaches them about grokking and water-sharing, he also inspires a transformation that will alter Earth's inhabitants forever...