Triton did not choose to be a soldier for the oppressive Spitnik regime. He was forced into it. Then he is given the options of killing innocent civilians or be sent to a camp which he would not survive.
Just when all hope appears lost, the situation dramatically changes, and he finds himself on the other side.
The Spitniks are determined to bring the desert moon Bahram under control. A rare element there would greatly accelerate their plans of conquest of other worlds.
The Bahramians are determined not to let the Spitniks have it. Triton could help. But only if he can win their trust. He must hurry since it is not just the freedom of the Bahramians at stake. It is the freedom of all people in known space.