Of the three books in the series (of four) and of those available at the time of writing, this is definitely the darkest of the lot. We get to see and experience both sides of the war from the Crutchians and from Cook's crew and associates.
The book starts a few years after the last book with Cook having been promoted to Commodore. Cook remains arrogant, childish, pedantic and usually always right.
The war remains bloody; however, Terran politics starts to get in the way with the seedy elements of leaders coming to the front.
As to the love story - well you will have to read the books yourself.
I'm looking forward to the conclusion to the saga when 'The Guardians of Peace' is published.