In a time like the present, three young people dream of the fabulous ruins of a decaying city somewhere in the distant future: the Kalpa. The dreams of Ginny and Jack overtake them without warning, leaving their bodies behind while carrying their consciousnesses forward, into the minds of two inhabitants of the Kalpa - a would-be warrior, Jebrassy, and an inquisitive explorer, Tiadba - who have been genetically retroengineered to possess qualities of ancient humanity. In turn, the dreams of Tiadba and Jebrassy carry them back, into the minds of Jack and Ginny. As for the dreams of Daniel, they are even stranger and more disquieting. Hunted by others with similar powers who seek the sum-runners on behalf of a fearsome godlike entity, Ginny, Jack, and Daniel are drawn despite themselves into a mission to rescue the future of their dreams.

Greg Bear is the author of twenty-eight books, which have been translated into a dozen languages. He has won two Hugo Awards and five Nebula Awards for his fiction. Darwin's Radio and Vitals are his most recent novels. He lives with his wife and two children in Washington State.