Robert Silverberg

The Second Trip is a 1972 science fiction novel by Robert Silverberg. Prior to its publication by Doubleday, it was published in serialized form in Amazing Stories from July to September 1971.

In Illinois, the one-hundred-foot Cahokia Mound spreads impressively across sixteen acres, and as many as ten thousand more mounds dot the Ohio River Valley alone. The Mound Builders traces the speculation surrounding these monuments and the scientific excavations which uncovered the history and culture of the ancient …