Artificial intelligence has been developed to a point where a human personality can be uploaded into a computer, achieving a sort of hybrid immortality. Astronaut Christian Brannock welcomes this technology, technology that will make it possible for him to achieve his dream of exploring the stars.
A billion years later, Brannock returns to earth to check on some strange anomalies. While there he meets Laurinda Ashcroft, another hybrid upload, with whom he joins forces in investigating Gaia, the supermind dominating the planet. They must learn the truth of her shocking and terrifying secret plans for earth.
Author: Poul Anderson