Desert sands have laid waste to the south-west of America. Las Vegas is buried. California - and anyone still there - is stranded. Any way out is severely restricted. But Luz and Ray are not leaving. They survive on water rations, black market fruit and each other's need. Luz needs Ray, and Ray must be needed. The night of the raindance, Ig explodes into their fragile family like a miniature missile. Two years old, undernourished, wild - the toddler needs Luz more than anyone. So they steal her. The only way to save themselves now is to escape. It's said there's a man on the edge of the Dune Sea. He leads a camp of believers. He can find water. Venturing into this dry heart of darkness, Luz thinks she has found their saviour. For the will to survive taps hidden powers; and the needed, and the needy, will exploit it.