It was the smell of his office that finally convinced him that he had returned home to civilisation. Paper, stale cigarette smoke and perspiration combined to create a peculiarly animal odour – as of working horses. Up until that point it had seemed oddly unreal – as though London, with its endless crowds, speeding traffic and retinue of decrepit pigeons was somehow an illusion and all the time he was back there in the solitude of the desert; the cool of the cave.

Wearily, he fell into his familiar chair, observing the chaos of his desk. Paper scattered everywhere. An overfull ashtray and half empty bottle of Scotch. He sighed, then flicked open his case and brought it forth: the impossible artefact that he had smuggled out of Jordan. He stared at the intricate mass of interlocking wheels: a palm-sized fragment of some larger machine. He wouldn’t believe it if he hadn’t excavated it from the flowstone himself. The basal layer, sealed beneath overlying deposits of enormous antiquity. Millions of years old.