The Nasqueron's star system has been cut off from the rest of Mercatoria civilization because their portal (the only means of faster than light travel) was destroyed by the Beyonders.

Slow Seers like Taak are a dynasty of researchers who attempt to glean information from the Dwellers' vast but disorganised knowledge libraries.

In a previous research expedition to the Dweller-inhabited gas giant Nasqueron, Taak inadvertently uncovered a book containing information about the legendary "Dweller List" of coordinates for their own private systems of wormholes.

He sets out to invade the Ulubis system from the Cluster Epiphany Five Disconnect while also aiming to possess the secrets of the Dweller portals.

A Mercatoria counter-attack fleet hurries to defend Ulubis against the Starveling Cult ships and their Beyonder allies.

Both fleets are forced to travel at sublight speeds, leaving the inhabitants of the Ulubis system anxiously wondering which will arrive first.

In a backstory, it is revealed that he has been out of sympathy with the Mercatoria for some time, particularly over their treatment of artificial intelligence, and has, in fact, been a Beyonder agent.

He can still piece together the secret from the remaining clues: every massive body has a region of zero-net gravitational attraction at its exact centre.

The novel ends with Taak, having left Ulubis and joined the Beyonders, suggesting to a lifelong friend he has just discovered is an artificial intelligence, "One day we'll all be free."