Polity Agent is the fourth novel in Neal Asher's popular Agent Cormac series.
From 800 years in the future, a runcible gate is opened into the Polity. Those coming through it have been tasked with taking the alien ‘Maker’ back to its home civilization in the Small Magellanic cloud. Once these refugees are safely through, the gate itself is rapidly shut down – because something alien is pursuing them.
From those who get through, agent Cormac learns that the Maker civilization has been destroyed by pernicious virus known as the Jain technology. This raises questions: why was Dragon, a massive bioconstruct of the Makers, really sent to the Polity; why did a Jain node suddenly end up in the hands of someone who could do the most damage with it? Meanwhile an entity called the Legate is distributing toxic Jain nodes . . . and a renegade attack ship, The King of Hearts, has encountered something very nasty outside the Polity itself . . .