Third in the series Theirs Not To Reason Why.
Ia, AKA Bloody Mary, is a powerful precog who has foreseen the destruction of all life in the Galaxy in just 300 years. After an exhaustive search of the timelines, she found one slim chance, a set of choices that lead to one person able to save us under certain circumstances. Now, it is up to her to make sure this path is followed by everyone else during the next 300 years, even after her death. To do this, she must become recognized as "The Prophet of a Thousand Years".
Now as Captain of TUPSF Hellfire, the most powerful warship in the Terran United Planets Space Force, she must guide her crew in shaping the future path to salvation. The Second Salik War is just a step in this path. Some must live and some must die, worlds will survive or perish, but she is the one who must decide and bear the regrets that not everyone can be saved. And even seeing the choices does not mean the necessary actions will take place.
Ms Johnson seems to write in four book blocks, so there is at least one more book involving Ia, possibly more. Hopefully, she will return to this universe that she has created after that. She has left a multitude of strings to pick up in other series, including the Sanctuary civil war, the Fire Girl, and the final confrontation with the Zida"ya in 300 years.