Her hair was dyed purple. She wore spandex. She was dancing alone, the young foreigner, swaying barefoot on the roof of a car parked at an utterly remote frontier in the rocky core of Asia, hard beside the Panj River that saws Tajikistan from Afghanistan -- a notorious opium smugglers' paradise at the southern edge of the Pamir mountains. The car had EU plates. But who was she? A belated pilgrim on the old hippie trail? A mystic? An addict? A tourist? An adventurer? It was impossible to know.

I raised my sweat-pickled hat in greeting as I shuffled past, chivying a tired cargo donkey, wind-chapped, and hollow-bellied from camping more than a month among the crags of Central Asia. I am walking across the world. For five years I have been pacing off the Earth as part of a project called the Out of Eden Walk, a storytelling pilgrimage along the pathways of the first ancestors who explored the planet during the Stone Age. To walk in this way -- continuously, day after river, month after continent, over a route that eventually will span 21,000 miles -- is to inhabit a state of daily wonderment. So the wilderness dancer was not really a surprise. Nor did I startle her. She didn't see me. Lost in the techno beats punching out of her car's stereo, she never even opened her eyes.