For millennia, humankind and the other intelligent races had studied the bizarre and unfathomable constructs of the legendary beings known as Builders. But for all that study, they were still no closer to figuring out who - or what - the Builders had been, or where they had gone. Then, on the world called Quake, in the midst of the violent planetary upheaval that was Summertide, a small group of humans and aliens witnessed the culmination of all those years of watching and waiting: the planet Quake opened up, and something came out - and it looked as if, at long last, the discovery of the Builders themselves was at hand.

All her life, Darya Lang had dreamed of finding the Builders, whose artifacts she had single-handedly catalogued for the rest of the universe. Troubleshooter and adventurer Hans Rebka had his own dreams of unraveling the mystery of those artifacts. To Louis Nenda and the Cecropian Atvar H'sial, the Builder artifacts represented a once-in-a-lifetime shot at untold wealth. And close behind them came the others: Councilor Julius Graces, who did not trust anyone to make first contact unassisted; the slavesJ'merlia and Kallik, who craved only a reunion with their masters; and the embodied computer E.C. Tally, charged with finding out just what the rest were up to.

The trail that began at Quake led to unexpected Builder artifacts full of traps for the unwary and answers for those who knew how to ask the questions. But the biggest question of all would remain an enigma, while their search unleashed the greatest threat to civilization ever imagined...