Sum up (made by basing myself on the novel):

After getting hit by an Interdictor (technology used to forcefully bring a ship back to normal space - can't be avoided by most ships - often used by pirates), MC notices that something is wrong: The opponents aren't "pirates" at all but old military ships. So he prepares himself. Thanks to that, he manages to avoid getting destroyed once the military ships start firing at him. They aren't interested in the other ship that MC was escorting at all and just continue to target MC.

In order to avoid getting hit, MC goes straight toward the battleship's blind spot and maintains a close distance. Due to that, all the enemy ships are unable to use their most powerful weapons as MC is using the battleship as a "shield". So they are forced to use smaller ships... against a ship that can obliterate those...

Mind you that MC could also use some torpedos against the enemy ships but, as they're technically "military", he judges that it's better to simply destroy the smaller ships and acts only in self-defense. Well... Another reason is that those torpedos are expensive and "destroying military ships" wouldn't allow him to collect any bounty at all.

After a short period of time, the Lt Commander Serena arrives with her fleet and demands that the enemy ships stop fighting & depower their engines. After all, they are from the same country so she can't really shoot them down without giving them an opportunity to surrender and get ready to be court martialed. However the enemies... Well... They completely ignore her and become more desperate, trying everything to bring MC down even if it means damaging the battleship.

After running out of patience, Serena finally orders her fleet to fire at the enemies. As he can't use the battleship as a shield anymore, MC takes some distance from his previous "shield". All the enemies are still focused on him, completely ignoring Serena's fleet (they don't want to fire on the military of their own country after all), even leaving their flanks exposed so they quickly take some heavy hits.

At the end, MC managed to hide himself by using a damaged heavy cruiser and he doesn't plan on leaving this place until Serena takes full control of the situation. Leaving his hiding spot would mean exposing himself after all... and the enemies might try to kill him once again. After a few moments, the enemy battleship finally surrenders and depowers its generator. The First Mate is now in command as the Captain has decided to take his own life.