It's the tale of three young men who join the Solar Guard to serve as Space Cadets (yes, really That's what the book calls them). It tells of the challenges that face them, and the way they triumph over adversity.
The alien spaceship was unthinkably huge, enormously powerful, apparently irresistible. It came from the void and settled on Earth, striking awe into the hearts of all who saw it. Its mission, however, was not conquest -- but a call for help! First contact was a job for the brilliant team of scientists, Arcot, Wade, and Morey. And what they received was an offer of an alliance against an invading foe so powerful that no known force could turn it back!
The Lexman Spacedrive gave humanity the stars, but at a fantastic price. Interstellar exploration, colonization and trade became things of reality. The benefits to Earth were enormous. But because of the Fitzgerald Contraction, a man who shipped out to space could never live a normal life on Earth again. Travelling at speeds close to that of light, spacemen lived at an accelerated pace..
In a world where Security is all-important, nothing can ever be secure. A mountain-climbing vacation may wind up in deep Space. Or loyalty may prove to be high treason. But it has its rewards.