I gave earlier books in the Serrano series a mixed review since the focus seemed to me uneven, veering from the inner thoughts of a teenager to the details of horse-riding to the occasional space battle. But in volume 2 the author has settled on a good balance. There are two main characters, both young women with great strengths and also character flaws that they're aware of and struggle with. One is a rising star in the space navy held back by her insecurity and background on a planet where women aren't expected to fight battles. The other is the daughter of a leading aristocrat, genetically engineered for courage and intelligence but spoiled by wealth and easy living.
In the first story of the duo in this volume, the first of the duo, Esmay Suiza (a distant relative of the Serranos who link the stories in the series) stars the book after having saved the day by mutiny in the previous volume. The authorities recognise her talent but she diffidently declines to go for seniofr command, so she is sent to serve as a junior officer on an obscure repair ship. This happens to be the site of a plot by the sinister Bloodhorde, and her resourcefulness is stretched to the full as the plot unfolds.
In the second story, both characters find themselves in advanced training together, and fall out violently, with rich girl Brun leaving the service and sailing off in her own ship, where she recklessly intercedes in a hijacking and is caught by a reactionary misogynist sect (loosely modelled on Texan survivalists). Esmay is suspecting of complicity...
Moon's writing is always fluent and engaging: you can readily see how the characters feel as they do, and want things to work out for them; as they are far from always successful, there's a good deal of suspense. The villains tend to be cardboard cutouts, though - the Bloodhorde are basically savage warriors from Central Casting, and the truly nasty pseudo-Texans are not much subtler. With that small reservation, it's a very good buy.