This is the fourth book of the Xenowealth series. I found Apocalypse Ocean gave me the connection to place and characters of the first book, Crystal Rain, while also containing easily as much action and adventure as the other two, Ragamuffin and Sly Mongoose. I think this is Buckell's best book yet, and I expect it will be one of my Hugo nominees.
The book starts with some of the classic tropes of a fantasy novel - young beggar queen of a dockside town is watching a dangerous looking interloper from the rooftops; she has arranged for him to run into trouble so she can observe what happens. A scared little pickpocket in her gang is intercepted months later by a warrior looking for that earlier transient, hoping to meet with his boss, seeking information. He escapes her as the rain starts, but she hunts him back down and the meeting is arranged.
But this is not fantasy, this is hard science fiction. The two warriors are cyborgs who helped found the Xenowealth, named Pepper and Nashara. Nashara has clones of herself that live purely as AIs, one of whom, Piper, runs one of their spaceships. The local beggar queen, Kay, is a rare survivor of the Caretaker class of genetically altered humans who were slaves to the alien Nesaru until the League liberated them - but not before the Nesaru killed many of them in an attempt to hide the evidence. As a Caretaker, she has been bred to be hypersensitive to human expressions - she can read people, and thus control them. Her family managed the other classes of slaves - the Runners, the Luminoids, the Ox-Men. That type of control, using other people as tools, is her special skill.
Kay has not yet figured out her goal in life, but her current goal is simple: to stay free of Alien dominance. And that goal is threatened; an Alien with a wormhole for a mouth is terrorizing her city. So she tries luring Pepper into a fight with it. He injures it, which is interesting, then is forced to flee into the ocean. But there's a lot more going on in this town than she knows. Her planet, officially a neutral area in the shaky truce between the League and the Xenowealth, is just one stop on the network of planets strung together by "grounded" wormholes. Ships can sail along this network, planet to planet. Are some of those ships part of an Alien invasion force? And why is the city in an ever-expanding Dead Zone, where most electronics don't work?
The pickpocket, Tiago, will play a bigger part in the coming events than he would ever have imagined. In the meantime, it rains. Well, they call it rain. Napalm mist from the Fire Valley floats over the mountains and scars the skin of anyone unlucky enough to be caught in it.
Both Tiago and Kay have some significant growing up to do, and the lessons Buckell weaves for them are rooted in fundamental questions of how people trust and cooperate. And fight. And dream.