Zephaniah Corcoran has just returned to Earth after a seven-year jaunt to Jupiter where his specialsome would say dubioustalents were put to the test in attempted communication with the Jovian cloud-whales. With no time to adjust to life on an Earth half alarmed and half fatalistic at the prospect of final catastrophe, he is headhunted for a reprise of his old job: being projected by the brilliant but asocial Walter Hallecks Coincidence-driven Sling into the far future to make empathic with the various successors to the human race. In the meantime, he is discovering a close and mysterious bond with Denise, a doctor of evolutionary biology and the younger sister he has hardly known, who has been noticed by the same big players who have noticed Zeph.