3 books in series

Twenty Planets

Twenty Planets is a 3-book series with 3 primary works first released in 1998 with contributions by Carolyn Ives Gilman.

Halfway Human

Twenty Planets

1998 • 7 Readers • 472 pages • 5

Dark Orbit

Twenty Planets

2015 • 37 Readers • 304 pages • 3.3

Arkfall

Twenty Planets

2010 • 3 Readers • 108 pages • 4