This mile a minute book starts with the discovery of a human skeleton buried under some rubble on the surface of the moon. It is definitely human, but it is hundreds of thousands of years old, and the space suit is not man-made. This is the story of how the human race overnight learns that it has a vast ancient interstellar legacy, all evidence of which had been completely wiped out by a series of atomic wars. This was Hogan's first book, and it was wildly successful. He wrote it on a dare because he was unhappy with the ending of 2001's Space Odyssey.