This book finishes the Dark Space trilogy. I reread the other two before starting it, and was glad I had done so, to track secondary characters and events. This one is a more internal book, despite the action at the end that leads to a satisfying conclusion. Much of the story here is watching Brady, along with Cam, Lucy, Doc, and the rest, coming to terms with the limitations of their experience as passengers with the Faceless.
These are very alien aliens, other than in their humanoid appearance. And despite living on their ship, our heroes are making very little progress in figuring out ways to find common ground. As the humans are forced to adapt to letting the ship's offerings feed them, slowly losing their tech to the constant moisture, Brady wonders what good they are possibly doing there. Then another Faceless ship joins them, and they find out that the hive-mind of their Faceless is not species-wide, and not unanimous.
The previous books were about both plot and relationship-building, but here Brady and Cam are rock solid. The focus turns to Brady's mental health, his self-perceptions as filtered through his past experiences, and the wider questions of whether humanity can ever really understand, or get understanding from, the Faceless. Sometimes Brady goes in mental circles, figuring things out intellectually, but unable to get past his unhelpful emotional reactions. He's still scared, still prone to turn that into anger, and still protective of those he cares about, in a situation where he's pretty helpless to protect anyone. He's very human, and having Cam and Doc and Lucy is what keeps him moving forward. (I'd have liked to see more child-like behavior from Lucy, but one could posit that her deprived childhood taught her to be stoic in the face of boredom and discomforts.)
Although one element of the ending sat a bit oddly with me, I found this book imaginative, with twists I didn't expect, and was impressed at the plausible happy ending pulled out of a difficult situation. Brady and Cam are still sweet together. I loved Doc, and found this a satisfying wrap up to the series.