Ancestral Night by Elizabeth Bear

Halmey Dz and her partner, Connla, make their living salvaging ships in outer space.  They spend all their time on their ship, sailing vast distances and rarely encountering any other life forms or even gravity.  It's a life that suits Halmey, her only other companions, the ship's artificial intelligence, Singer, and the two cats that travel with the ship.  It's a fairly calm life far from the early stress and disasters that marked her earlier years.

That changes when the crew encounters a huge prize.  It's a ship larger than any they have seen and will take care of their accumulated debts plus give them shipping supplies for the future.  Halmey goes into the ship and discovers a nightmare.  It is a abbatoir where one of the oldest lifeforms in the Synarche, the massive Ativahikas, are killed and rendered down.  Before she can leave the ship, she is infected with a foreign substance under her skin.  The prize is taken from them at the last minute by a pirate ship.

The crew takes shelter at the nearest Synarche outpost where they report the crime.  They are not amused to find the pirate ship there also and soon Halmey meets Zanya Farweather, captain of the pirate crew.  Farweather seems to want something from Halmey although it's unclear if its information or a romantic interest.  Regardless, the crew leaves the outpost having made their report and the acquaintance of the law on the outpost, a giant mantis creature.

As they travel, the substance in Halmey's skin helps them start to navigate and soon they encounter a new part of space and a prize that is full of ancient technology that will take the Synarche light years beyond anything they currently have.  Unfortunately, Farweather has followed them there and soon she and Halmey are trapped on the new prize and it's clear that war has been declared.  Can Halmey and team manage to avoid the pirates and bring home the biggest salvage gain ever?

Elizabeth Bear has written a fascinating space fiction.  The characters are interesting and the relationships between different lifeforms is intriguing.  The novel delves into questions such as what makes life one to be treasured rather than exploited, what are the boundaries of intelligence, is there a true morality that should be held to across species and what is the place of society?  The reader will slowly unpeel the layers that bring these questions into play and hurtle towards an exciting ending.  This book is recommended for science fiction readers.