You've been stranded in space, locked up and kept in stasis in a rescue pod. Then there's a fleet, picks you up, welcomes you on board as a legendary hero. Obviously someone didn't keep his mouth shut when they left you to die in defense of their retreat... But had they known you would have survived, they might not have mythologized you quite so much. Anyway... All command officers are executed by the enemy and you have to sort it out.
This is the second book. In the previous one, you save your fleet from annihilation. In this one, you start pounding away at the enemy.
What is rather strange is that it's quite difficult to stop reading. It's not written terribly well. There's too many long monologues. There's not quite enough actions. The space battles sometimes makes you think of the early books of R.A. Salvatore, losing himself in descriptions of fights of which you knew they wouldn't end with the death of the hero. There's not much psychological development of the main character (or actually, of any of the other characters). There's a little too much omnipotence of Jack Geary (obviously, because the author Jack Campbell sees himself as a Jack Geary in real life).
So. This story is really a tale of morals on why the military has the rules it has (discipline, order, military justice etc. etc.). The enemy is the bad guys mainly characterized by the fact that they aren't good military (i.e. don't have any honor, mistreat prisoners etc. etc.).
And yet... It's not really bad either. And quite difficult to stop reading. I think I'll have to buy the 3rd book in this series as well.