In time the skies cleared – but the remnant American ice caps had been destabilised. One tremendous sheet had been draining south down the Mississippi river system. Now huge volumes of cold water flowed through the inland sea that covered the Gulf of St Lawrence, chilling the north Atlantic. Around the world the ice spread from the north once more, and life retreated to its southern refuges. This new winter lasted a thousand years.

But even as the ice receded again, even as life took back the land once more, the world was not at rest. Meltwater fuelled rising seas, and the very bedrock rebounded, relieved of the weight of ice – or it sank, in areas that had been at the edge of the masses of ice and uplifted by its huge weight. In a process governed by geological chance, coastlines advanced and receded. The basic shape of the world changed around the people, constantly.

And to north and south of the rich hunting grounds of Europe’s north land, generation on generation, the chill oceans bit at the coasts, seeking a way to sever the land bridge.

2

The Year of the Great Sea: Winter Solstice. The day of Ana’s blood tide, with her father missing and her mother dead, was always going to be difficult. And it got a lot worse, early that very morning, when the two Pretani boys walked into her house.

Sunta, Ana’s grandmother, sat with Ana opposite the door. Ana was holding open her tunic, the skin of her exposed belly prickling in the cold air that leaked in around the door flap. Sunta dipped her fingertips in a thick paste of water, menstrual blood and ochre, carefully painting circles around Ana’s navel. The sign, when finished, would be three big concentric circles, the largest spanning Ana’s ribs to her pubis, with a vertical tail cutting from the centre down to her groin. This was the most ancient mark of Etxelur, the sign of the Door to the Mothers’ House – the land of ancestors. Later this painting would be the basis of a tattoo Ana would carry through her life.