Absolutely delightful and splendid.
Linda Nagata continues her brilliant saga of a galactic war between autonomous alien warships, the murderous Chenzeme, and one particular society of post-humans amongst the myriad diaspora of humanity, some seven hundred years past the events of the last book, Vast. This story is the first in a set of three within the Nanotech Succession series universe. I'll advise reading those before starting this, even though they're mostly standalone, for that diverse maximum reading pleasure!
In this one, we follow Urban as he comes into the Deception Well star system camouflaged as a Chenzeme war courser and picks up a crew to explore the Hallowed Vasties, which has become a kind of inverted frontier, seeing as the star systems previously enshrouded within Dyson Swarms from whence humanity emigrated and colonized nearby stellar systems and are now disintegrated and visible several millennia henceforth. So...he sets off on a quest from the frontier colony to the first colonized systems, comprising the Sol System.
The science, though wondrous, is quite fluid and feels really intuitive. Even though it's fiction, the writing style is very good, and the immersive telling (told in a second-person perspective) of the villain is atmospheric. They, Urban and Lezuri, fight a protracted war in both real and cyber spaces that'll ultimately determine the voyage's fate and destination, the crew's future, and their basic understanding of the universe and cosmos.
Lastly, we finally get some insight into the BDOs and wondrous megastructures hinted at throughout the series, and this is speculative science fiction at its best. Linda Nagata writes science fiction just how I like it, a great yarn of the thought-provoking kind!
Highly Recommended.