It's been fifteen years since Amanda Ripley's mother disappeared aboard the deep space towing ship Nostromo. And for fifteen years, Amanda has suspected there was more to her mother's story than meets the eye.
The body of a foreign student is discovered in the streets of the down at heel city of Besźel. Cases like this are run of the mill for Inspector Tyador Borlú of the Extreme Crime Squad - until his investigations uncover evidence that the dead girl had come from another city called Ul Qoma. But the relationship between the two cities defies comprehension and will challenge everything Borlú holds dear.