This is a rousing adventure cast in the mold of Conan and Thongor, with exotic races, magical dangers, and a scifi twist all its own. One rather glaring continuity error mars this fine tale, and probably cost the editor his/her bonus in 1966. If you are a fan of heroic/barbaric fantasy or planetary romance, you will find plenty to love about the mighty Ulmekoorian and his companions.
This author also wrote the Agent of T.E.R.R.A. series as Larry Maddock.