E.C. Tubb 
Eye of the Zodiac 
The Dumarest Saga Book 13

In the course of a continuing quest for his legendary birthplace, Earl Dumarest befriends a young man who says his home world was called Nerth.New Earth, perhaps? Or even the original planet Dumarest seeks? He must find out.And so Dumarest comes to Nerth — to discover that the Cyclan, his prime enemy in the cosmos, is already there . . . together with mysteries and terror that defy the imagination!(First published 1975)