Descendants of a long-marooned group of humans struggle with mutations and infertility, and if a cure cannot be found they are doomed to extinction.

The colony's doctor, Anaïs, herself suffers from a sexual deformity. However, her world is turned upside down when she discovers that the preserved corpse of a long-extinct native race carries exactly the same deformities as herself.

What is the connection? And can she find the answer to this mystery that has reached back from time to haunt both her and the colony struggling to survive against impossible odds?

This edition include eight new appendices by Stephen Leigh.