Hellburner

Hellburner is a direct sequel to Heavy Time and, according to Cherryh, these are the only two books that need to be read in order, which says something about how she's constructed the whole Company Wars saga with multiple entry points into the narrative.

Cherryh takes the same approach as Heavy Time, which I think bears out the general theme of the little guy trying hard to piece together what the hell is going on while at the mercy of people and systems far more powerful than they are. It's told in very close third person POV, which can be hard going at times, but it gives a good sense of the characters being trapped and fighting to survive.

The hints and revelations they do manage to uncover point to an extraordinarily detailed set of machinations, powerplays and political maneuverings around the success or otherwise of the Hellburner project. Every bit as richly detailed as the world of the belters and the company in Heavy Time.

Hellburner itself is a prototype ship designed to give Earth an edge in the ongoing war with the Union and Cyteen (as recounted elsewhere in the series). And again, Cherryh never has a character explaining how the ship and all the new technology work. In keeping with her general approach, everyone 'in novel' knows this stuff and what the hell is going on, so why explain it? That leaves the reader to piece everything together, which may not be to everyone's taste, but I certainly enjoyed it.

I could say more about the actual plot, but it would probably seem quite bare in the recounting. What really makes Hellburner a gripping read is the skill of Cherryh in taking us inside the lives of her characters and her world.

This is chronologically book 2 in the Company Wars sequence and happens not long after Heavy Time. This takes those characters and pushes them into a story about building the military that is going to go and make the colonies behave the way Earth expects them to.
Some of the same plot elements from Heavy Time are to the fore (trauma induced mental health for example), but this is a more political story.
Politics in getting the military funded.
Politics in getting the military going.
Politics in the military, who is in charge, who makes the decisions.
There is also an explanation of the motivations of people for being in the military. For a lot of this it's volunteers who want to play with the shiniest of toys. For others, backing up friends. For others, nowhere else to go. Most interestingly, there is an exploration of why some of the spacefaring clans want to fight. Pure xenophobia. This is a mind bend because they themselves have been bent far away from the human 'norm' by their existence to date.
Plenty to chew on here in a tight novel. Recommended.