Golan Trevize has chosen the future of humanity, and the choice was Galaxia — a galaxy-wide superorganism in which every world, every creature and every grain of sand would share a single consciousness. He made that choice on instinct, and he cannot say why. To settle it he needs the one fact the Galaxy has lost: where humanity began.
Trevize sets out with the historian Janov Pelorat and Bliss, a woman of the group-mind planet Gaia, to find the legendary Earth — a world scrubbed from every library and archive so thoroughly that even its existence is disputed. The search takes them to Comporellon, which claims to be the oldest inhabited world of all, and then out to the long-abandoned Spacer planets, Aurora, Solaria and Melpomenia, each holding a fragment of the answer and a reason to leave in a hurry.
Published by Doubleday in 1986, Foundation and Earth is the fifth Foundation novel and the direct sequel to Foundation's Edge. It is the last book in the sequence's internal chronology, and the one in which Asimov draws his Robot, Empire and Foundation novels together into a single future history.