Stone Spring — Stephen Baxter

Ten thousand years ago, a vast and fertile plain exists linking the British Isles to Europe. Home to a tribe of simple hunter-gatherers, Northland teems with nature's bounty, but is also subject to its whims.

Fourteen-year-old Ana calls Northland home, but her world is changing. The air is warming, the ice is melting, and the seas are rising. Then Ana meets a traveler from a far-distant city called Jericho-a city that is protected by a wall. And she starts to imagine the impossible...