Jacqueline Lichtenberg wrote the first published book in the Sime~Gen universe (Unto Zeor Forever) in 1974. She was joined by Jean Lorrah who wrote First Channel which was published in 1980. This lot has about half of the series plus some not in the series but by same authors. The Sime~Gen novels can be read individually, by order of publishing, or by chronological order. 

The Sime~Gen Universe is set in a future where humanity is divided into two subspecies: Gens, who produce a life energy called selyn, and Simes, who must extract selyn from Gens to survive. The series explores themes of coexistence, survival, and the emergence of "channels," Simes who can take selyn without killing Gens, leading to a fragile unity between the two groups.