Robert Silverberg 
At Winter’s End 

The Long Winter is over.The People of the New Springtime must go out and reclaim their world.For generations the survivors of the cataclysm have sheltered in cocoons buried in the earth and waited for the gods to grow tired of hurling down death-stars onto a frozen world. Now it is time for Koshmar and the boy-chronicler, Hresh, and the rest of Koshmar’s tribe to emerge into the sun. A strange and savage landscape awaits them, where rat-wolves, bloodbirds and soulless hjjk-men stalk – and terrifyingly altered other creatures.In the ruins of Vengiboneeza, the ancient capital of the sapphire-eyes folk, Hresh dares to celebrate their triumph – and suffers a shattering defeat at the realisation of a great and terrible truth.(First published 1988)