Welcome back, Black Jack! Before I get into any nitpicks, let me open with the fact that I finished this book in record time. I have limited time to read, so some books can take me 2 months to finish. I was done with this one in a couple of weeks. Now I have to wait.
This story was fast paced and very entertaining. I liked that Jack Campbell didn't rush Black Jack and the fleet through Syndic space and into alien space. The time to get the fleet ready, problems found with the ships due to their design/combat life-expectancy, character relations... All seemed credible and helped build up interest in the characters. Especially since I haven't read anything about them in about a year - nice to get a reminder.
Here are some things I wasn't as fond of. This book was too open ended. I know it's part of a series, but in the first Lost Fleet series, I remember the books each ending with a significant event - something came to a close.
For example - Dauntless went through the story with Black Jack getting use to being in command of a fleet suffering from hero-worship while dealing with his own issues and losses. The book ended with a climactic battle. While the reader knew the series would continue, there was a feeling of closure for that part of the story.
The trickery/politics involved were entertaining. The concerns that the end of the war with the Syndics causing a rift within the alliance seemed completely credible. I was actually drafting a short story for a Star Trek fanfic contest that followed this (with the Romulans friends, there are no major threats, so some worlds would likely pull out of the Federation).
The return of Victoria Rione was expected. I love her comment "I'm a bitch, and I have to stay in practice." in reference to provoking Captain Desjani. There's a lesson here. Profanity can highlight a scene, but I think profanity is overused in literature, especially military sci-fi/space opera. Jack Campbell crafts an excellent story with good dialogue without profanity. When he uses it, it's because there's no better way to phrase it.
I would have preferred if this book ended with the fight against the aliens they sought. The good part of that was the development of an effective battle strategy. Saving some prisoners was good too. Maybe hint that there was another species possibly involved, but DON'T bring them in yet. I would have preferred the Death Stars wait until the next book.
I'm mixed on the development of Jane Geary. Good captain and pulled off a good strategy (deliberately disobeying Admiral Geary), but I'm not sure if I like how defiant she seemed to be.