Man has colonised Mars and Venus. Radiation-induced psychic mutants are now common (except on Earth) and are being used to wage clandestine war against Earth.
Following an alarming near contact between long-range Earth exploration ships and something rather alien, some super psychics are recruited to stop the rebels. The super psychics are actually "possessed" by higher intelligences that are hiding Earth (which is their nursery) from the approaching telepathic "racist" Denebs.