Then, as if the space and sky overhead had suddenly been torn open, there was a flash of light followed by the roar of a tremendous explosion. The ground trembled. The air seemed to moan in agony. Strong and Astro wheeled around and looked toward the tower that shimmered in the light of the late afternoon sun. To their horror, they saw the unmistakable mushrooming cloud of an atomic blast rising in the synthetic atmosphere behind it.
"By the craters of Luna—" gasped Strong.
A second flash and explosion rocked the prison asteroid and suddenly the tower disappeared. Almost immediately, a spaceship appeared over the small planetoid and began systematically pounding the surface installations with atomic blasters.
"Captain Strong," cried Astro. "Tom and Roger—they were in the tower!"
"Come on," yelled Strong, "we've got to get back!"
"You ain't going nowhere, Strong," snarled Coxine behind him. "I've been waiting a long time for this!" He suddenly struck the Solar Guard officer with a heavy rock and Strong slumped to the ground unconscious. Before Astro could move, Coxine smashed him to the ground with a blow on the back of the neck. They both lay deathly still.
Then, as the atomic bombardment of the penal asteroid continued, the giant space criminal jumped into the jet car and sped away.
CHAPTER 11
"Fire!" bawled Major Savage to his crew of gunners.