They walk away from the house, man and woman, the yellow door behind them, the silver car by their side. We're too late. We shall follow them from here.

Nearby, at the end of the previous Ice Age, the river known as the Thames forms its present course.

They walk further along the road, past the pattern of houses and cars. They stop outside a pub, then go inside, and emerge shortly afterwards with a drink. High above their heads on the wall is a painting of two ships - one a sailing ship, the other a German destroyer which we recognise from the First World War. They haven't seen the painting yet. The number 97 is painted at its base.

People start settling in the area. Their remains will eventually lie undisturbed for nearly 6,000 years.

They walk past a sign upon which is written 'Slow Children Playing'. They slow when the path widens into a square area that contains two cars. In the bushes just beyond rubbish lies in piles, anticipating its future archaeology.

A burial ground has been found nearby, on Sunbury Common, which dates back to the Bronze Age, nearly 4,000 years ago.

They walk slowly towards a bench which overlooks the meadow. Willow trees mark the edge of the bank and the edge of the stream. A man enters the meadow on the right. He is dressed in a shirt and tie and looks like he has just returned from the office, although it is only early afternoon. In each of his hands is the smaller hand of a child, a small boy and a small girl. With them