The four men had been scrutinized, watched, investigated, and intensively trained for more than a year. They were the best men to be found for that first, all-important flight to the Moon--the pioneer manned rocket that would give either the East or the West control over the Earth.<br><br>Yet when the race started, Adam Crag found that he had a saboteur among his crew ... a traitor! Such a man could give the Reds possession of Luna, and thereby dominate the world it circled.<br><br>Any one of the other three could be the hidden enemy, and if he didn't discover the agent soon--even while they were roaring on rocket jets through outer space--then Adam Crag, his expedition, and his country would be destroyed!
(Summary by Jeff Sutton) <p>