"Del Rey."

Takes place in the same universe as the author's "Perdido Street Station," but is a stand-alone novel

Aboard a vast seafaring vessel, prisoners and slaves are being transported to a fledgling colony of New Crobuzon. When the ship is besieged by pirates, the senior officials are executed, and surviving passengers are brought to a floating city constructed upon the hulls of pirated ships, a place whose leaders harbor a sinister agenda.