When an old foe returns and takes control of a doomsday weapon, an admiral who feared his time was over must utilise all the tricks his experience taught him to save his ship and crew.

Hi Zodrak.

1. Why does the old foe use a doomsday weapon only on one ship? He could do more damage than that I suspect and put many more in danger, which would up the stakes, making the longline stronger
2. The admiral seems like a blank page. You could shorten “who feared his time was over” by using something like world-worn as an adjective. It hints to a psychological state. Also the antagonist is missing a descriptive adjective which makes it hard to envision the struggle between them.
3. What doomsday weapon are we talking about here? Making it specific might make it easier to visualise the story concept.
4. It sounds like hero and villain have history together, maybe that could be hinted at as well if it doesn’t make the longline too long…