Aurelio Zen was dead to the world. Under the next umbrella, a few desirable metres closer to the sea, Massimo Rutelli was just dead.

The two men were different in just about every other respect too. Zen was wearing a short-sleeved cotton shirt, lightweight wool trousers and leather sandals, and lay back in his deckchair in the shade of the beach umbrella with the brim of a Panama hat lowered over his eyes. Massimo Rutelli was naked except for a minuscule black swimsuit and an orange towel loosely draped over his upper back, and was lying prone on the green canvas lounger provided for sun-worshippers, his hands resting on die surface of the perfectly smooth sand. But the main difference between them was that one was dead and the other was dreaming.

The dream was one that Zen had had recurrently for many months now. He had no clear idea how long exactly. His memories of the period since l’incidente were as partial, confused and unreliable as those of his childhood. As for the dream, it always involved three fixed elements – a bridge, an imminent disaster, and a happy ending – but the specific properties, locations and special effects varied from version to version.

The bridge, for example, could be as small as a concrete culvert under a motorway, or a massive structure so long that neither end was visible from the middle. On one occasion it had been a wooden trestle across a fast-flowing river. A steam locomotive pulling a train was approaching the far side while the ignited fuse fizzed down through the undergrowth towards the stacked sticks of dynamite. But it had been lit too late, and the carriages crossed safely before the trestles were flung spectacularly up into the air, to fall again like so many matchsticks.

Another instance had been a rope footbridge suspended across an abyss whose depths were concealed by thick, slowly coiling currents of mist. In this case the threat had come in the form of a plague of shiny black beetles nibbling away at the ropes with their