The Planet Savers is a science fantasy novel by American writer Marion Zimmer Bradley, part of her Darkover series.

Desperate to discover a cure for the cyclical 48-year-fever, known as Trailmen’s fever, Dr. Randall Forth persuades a colleague, Dr. Jay Allison, to undergo hypnosis.

Jason is asked to lead an expedition into the Hellers to collect medical volunteers from among the Trailmen.

Accompanying him are Rafe Scott, Regis Hastur, Kyla Raineach, a Renunciate guide, and several others.

The Old Ones of the Sky People (Trailmen) inquire why Jay/Jason has brought an armed party of humans to their nest.