E.C. Tubb 
Symbol of Terra 
The Dumarest Saga Book 30

Clues from Angado, clues from the lady Govinda, all leading Dumarest on in his search for the lost Planet Earth. But first they lead him to a collector of ancient wisdom called Tama Chenault.But Chenault is not all that he seems, and Dumarest is forced to bargain for the information he seeks. In return he must pledge allegiance to Chenault’s deadly plan . . .(First published 1984)