The Algebraist

As complex, turbulent and spectacular as the gas giant on which it is set, this novel from Iain M. Banks is space opera on a truly epic scale.

"An enormously enjoyable book, full of wonderful aliens, a sense of wonder and subtle political commentary on current events." –Publishers Weekly (Starred Review) 

It is 4034 AD. Humanity has made it to the stars. Fassin Taak, a Slow Seer at the Court of the Nasqueron Dwellers, will be fortunate if he makes it to the end of the year.

The Nasqueron Dwellers inhabit a gas giant on the outskirts of the galaxy, in a system awaiting its wormhole connection to the rest of civilization. In the meantime, they are dismissed as decadents living in a state of highly developed barbarism, hoarding data without order, hunting their own young and fighting pointless formal wars.

Seconded to a military-religious order he's barely heard of - part of the baroque hierarchy of the Mercatoria, the latest galactic hegemony - Fassin Taak has to travel again amongst the Dwellers. He is in search of a secret hidden for half a billion years. But with each day that passes a war draws closer - a war that threatens to overwhelm everything and everyone he's ever known.
"Banks is a phenomenon...writing pure science fiction of a peculiarly gnarly energy and elegance." –William Gibson

"Banks writes with a sophistication that will surprise anyone unfamiliar with modern science fiction." –The New York Times
For More from Iain M. Banks, check out:

The Culture series:
Consider Phlebas
The Player of Games
Use of Weapons
The State of the Art
Excession
Inversions
Look to Windward
Matter
Surface Detail
The Hydrogen Sonata