This book is a spinoff from David Weber’s Honor Harrington series. Eric Flint imho is a much better author then David Weber, and the book is really well structured. Not sure how to explain it without giving anything away, it has space stuff, political intrigue, evil slavery organizations, a giant casino space station ( 
) and what I think is a very intriguing, emotionally satisfying ending.
Anyone who hasn’t should check out the Honor Harrington series too (especially the earlier books). I mean, what nerd can resist a hot starship captain who can kick the ass of most everyone she meets, is a genius at tactics, etc? 
Joe