Mind's eye - Paul McAuley

When he chances upon a strange piece of graffiti daubed on the walls of a north London restaurant, the violence of his reaction takes Alfie Flowers by surprise. The thorny circle of dashes and zigzags seems to reach right inside his brain - and provokes a flashback to a terrifying childhood incident. The incident Alfie has spent his life trying to forget.
Convinced the graffiti artist possesses the clues to his past, Alfie sets out to track down the elusive 'Morph'. His search will lead him to the mysterious Nomads' Club and a secret history of espionage, culminating in the disappearance of Alfie's father over twenty years before.
But the real secret of the graffiti patterns - or 'glyphs' - is to be found amidst the chaos of post-war Iraq. There, within the shadowy depths of an ancient network of caves, Alfie will uncover the powerful and disturbing truth behind the rituals of a strange, prehistoric society.
But there are others seeking the source of the glyphs. People with sinister and dangerous motives - and if they were to succeed in their aims, the consequences would be too horrible to contemplate...