The Thucydides Trap - Imperials Saga, #5

Thudydides Trap: A point when one great power threatens to displace another, war is unavoidable.. Thracius "Tracy" Belmanor has struggled to do his patriotic duty in the wake of the loss of the love of his life the Empress Mercedes de Arango. Amid a desperate war, the Solar League cannot afford his grief, not the political instability of admitting the depth of their relationship. It is for duty alone, both as a soldier and a father, that Tracy has entered into an arranged marriage that makes him part of the royal family and will hopefully stabilize the throne even as civil war looms.
However, a new danger has been revealed that will lead to extinction on a galactic scale unless the humans can find a way to defeat the looming threat. Not only from this mysterious force destroying all in its path, but also from a secret about the human race itself. Against a backdrop of war and loss can Tracy and Mercedes ever find their way back to each other?