The stick broke as he redoubled his efforts. He hastily tore another from the branch behind him, and when that broke too used his boot to free the package. Breathing hard, he unwound the oilcloth, revealing three blocks wrapped in silver foil and plastic shrink-wrapping. They were about the size and shape of a cork float, but much heavier — precisely one kilogram each, in fact. Giacomo carefully lifted them in turn and transferred them to the canvas bag. Then he added the oilcloth wrapping and fastened the bag before turning for home.

The torch beam wavered and probed the darkness all around, seeking the gnarled bough which pointed the route home. It was nowhere to be seen.

Giacomo searched the shrubbery in increasing desperation until he found the broken branch entangled in the thorns. It must have keeled over when he snapped part of it off to use as a spade. For a moment he almost gave way to panic. Then, with an effort, he got a grip on himself and started to study the undergrowth all around. It must be that way, surely, to the right of that squat, lopsided shrub. Yes, that was it. He recognized it.

A few metres further on, the path, if that’s what it had been, petered out in a mass of briars twice as high as a man. He must have been mistaken. He started back, but he was unable to find the clearing where the cache had been located. Then he saw what looked like one of the markers guiding him back to the boat and threw himself at it, plunging through the shrubbery like a speedboat through breaking waves, ripping and tearing the undergrowth apart until its spiky tendrils fouled his limbs and brought him up short in an impenetrable mass of brambles.

Instinctively he glanced up at the sky, but the nebulous wash of cloud drifting in from the east had swallowed the stars. The evil jungle, its roots fattened on hundreds of thousands of human skeletons, pressed in on every side, shutting out the world.