Empire in Crisis

The Empire is large, old and is on the verge of being torn asunder as ambitious Fleet Admirals contemplate overthrowing their new Emperor by force. As if that wasn't bad enough, the Empire is under attack by a powerful, unknown alien race that originated from the other side of a huge rift separating one part of our spiral arm from another part. The Emperor has to not only win the war but also keep his head (literally).
His best chance for success is a relatively junior officer, who survived the rift attack and may be courtmartialed for it. This novel has it all, space battles, grand strategy, political intrigue, betrayal, sacrifice and an ending that will blow your mind.