No species has ever reached for the stars without the guidance of a patron--except perhaps mankind. Did some mysterious race begin the uplift of humanity aeons ago? Circling the sun, under the caverns of Mercury, Expedition Sundiver prepares for the most momentous voyage in history--a journey into the boiling inferno of the sun.

Brin's tales are set in a future universe in which no species can reach sentience without being "uplifted" by a patron race. But the greatest mystery of all remains unsolved: who uplifted humankind? The Terran exploration vessel Streaker has crashed in the uncharted water world of Kithrup, bearing one of the most important discoveries in galactic history. Below, a handful of her human and dolphin crew battles armed rebellion and a hostile planet to safeguard her secret--the fate of the Progenitors, the fabled First Race who seeded wisdom throughout the stars.

Brin's tales are set in a future universe in which no species can reach sentience without being "uplifted" by a patron race. But the greatest mystery of all remains unsolved: who uplifted humankind?

As galactic armadas clash in quest of the ancient fleet of the Progenitors, a brutal alien race seizes the dying planet of Garth. The various uplifted inhabitants of Garth must battle their overlords or face ultimate extinction. At stake is the existence of Terran society and Earth, and the fate of the entire Five Galaxies.

The planet Jijo is forbidden to settlers, its ecology protected by guardians of the Five Galaxies. But over the centuries it has been resettled, populated by refugees of six intelligent races. Together they have woven a new society in the wilderness, drawn together by their fear of Judgment Day, when the Five Galaxies will discover their illegal colony.

Then a strange starship arrives on Jijo. Does it bring the long-dreaded judgment, or worse--a band of criminals willing to destroy the six races of Jijo in order to cover their own crimes?

For the fugitive settlers of Jijo, it is truly the beginning of the end. As starships fill the skies, the threat of genocide hangs over the planet that once peacefully sheltered six bands of sapient beings. Now the human settlers of Jijo and their alien neighbors must make heroic--and terrifying--choices.

A scientist must rally believers for a cause he never shared. And four youngsters find that what started as a simple adventure--imitating exploits in Earthling books by Verne and Twain--leads them to the dark abyss of mystery. Meanwhile, the Streaker, with her fugitive dolphin crew, arrives at last on Jijo in a desperate search for refuge.

Yet what the crew finds instead is a secret hidden since the galaxies first spawned intelligence--a secret that could mean salvation for the planet and its inhabitants or their ultimate annihilation.

The brutal enemy that has relentlessly pursued them for centuries has arrived. Now the fugitive settlers of Jijo--both human and alien--brace for a final confrontation. The Jijoans' only hope is the Earthship Streaker, crewed by uplifted dolphins and commanded by an untested human.

Yet more than just the fate of Jijo hangs in the balance. For Streaker carries a cargo of ancient artifacts that may unlock the secret of those who first brought intelligent life to the Galaxies. Many believe a dire prophecy has come to pass an age of terrifying changes that could end Galactic civilization.

As dozens of white dwarf stars stand ready to explode, the survival of sentient life in the universe rests on the most improbable dream of all--that age-old antagonists of different races can at last recognize the unity of all consciousness.