The Killer Thing

The protagonist, Captain Ellender Tracy, called Trace by his comrades, is a product of customs similar to those of the Spartans. At 12, he was placed in a military camp where he was trained to be a soldier in the imperial space navy. He knows that what is best is what makes Earth and humans more powerful. However, he and those he serves meet up with a force they never expected: a robot invented by one man on a conquered world that is even more powerful than his creator ever knew.