The arrival of a generation ship at a new world ignites conflict between its inhabitants and the long-established human population. Captain Perceval and the angel Nova must navigate the delicate first contact with the inhabitants of Grail, who call their home Fortune, while simultaneously uncovering a murderer among their own crew. The genetically altered humans of the Jacob's Ladder face suspicion and hostility from the Fortune inhabitants, led by Premier Danilaw, who fears not only external war but also internal strife as factions vie for control. The narrative unfolds across the approaching generation ship and the alien world, exploring themes of identity, xenophobia, and political maneuvering.

This novel concludes Elizabeth Bear's space opera series, bringing together themes of heroism, sacrifice, intrigue, and betrayal. The narrative focuses on the complex challenges of first contact between a genetically advanced human crew and an established population on a new world, while also weaving in a murder mystery. The story delves into political tensions both between the two human groups and within the arriving ship's command structure. The premise suggests a rich exploration of societal conflict and the definition of humanity.