'The Iralians were humanoid and techically free citizens of the Galactic Empire. But as slaves they were prized above all others, for they had the unique capacity to transmit acquired knowledge through heredity. And so when the space mercenary Wanderer was hired by GLASS (Galactic League for the Abolition and Supression of Slavery) to take a cargo of Iralians home it was going to be a simple task!' (www.bertramchandler.com).
Covers by Kelly Freas (Nebula Alert) and Peter Michael (Rival Rigelians). Source: www.antiqbook.co.uk)
Series:yAce DoublesAce Books
New York (City):Ace Books,1952-1978Z18490601952series - publisher novel
Ace Books began publishing genre fiction in 1952. Initially these were mostly in the tête-bêche (double) format, but they also published a few single volumes in the early years. The tête-bêche format was discarded in 1973, with later doubles being published adjacent to each other. Between 1952 and 1968, the books had a letter-series identifier; and after that date they were given five-digit numeric serial numbers. Ace stopped publishing its doubles series sometime around 1978.