Raiders from the Rings

The underground people of Earth were united in terror and desperation against what they considered a frightful threat from the skies. They had sent a mighty armada into space, rushing in lethal orbit toward Mars. The Spacers—- still really Earthmen themselves—- were poised for the counter-blow. The great fleet at Asteroid Central had sufficient warheads to reduce Earth to a cinder. But there was a third force, watching...