I reviewed Starhammer here, The Vang: The Military Form is Christopher Rowley's sequel and middle part of what is loosely a trilogy: the first book is effectively a prequel to the second book, and the third is effectively a postscript. As I said before, the story telling is compelling, and like before I found myself picking the book up in spare moments to read a few more pages.
The story takes place a thousand years after the events in the first book, and mankind has spread throughout the galaxy, free from the threat posed the Laowans who dominated the first novel. But, the threat of the Vang remains, mostly in remnants of their technology. This book starts with a crew who finds something interesting in space, the kind of something that could make them very, very rich or very, very dead.
It's not much of a spoiler to say that the later is closer to what actually happens, as in lots of people die as the consequence of waking a military form Vang, which then proceeds to do what it does best: conquer lesser forms by assimilating them. There's several twists and a wry commentary on how rulers demands mean that the military is not allowed to do what is necessary; and that's just from the Vang perspective.
Had to go away and start reading the third when I finished this, which says everything you need to know really.