4 books in series

Twenty Planets

Twenty Planets is a 4-book series with 4 released primary works first released in 1998 with contributions by Carolyn Ives Gilman.

Halfway Human

4 Twenty Planets

1998 • 13 Readers • 472 pages • 3.8

Dark Orbit

4 Twenty Planets

2015 • 49 Readers • 304 pages • 3.2

Arkfall

4 Twenty Planets

2010 • 3 Readers • 108 pages • 4

Dark Orbit: A Novel

4 Twenty Planets

2015 • 1 Reader • 304 pages