“I’ll try to hold it.” Sorrel had never spent this long outside, never walked this far, never slept without a roof over her head. Maybe they could stay here forever, a life stripped down to nothing at all. But they would need food and water. And other people. Her last thoughts were of Sesame – she had not read her friend’s last message. Maybe she and her family were now at the bottom of the Immersion Zone.

It was afternoon before her mother woke her. “You let me sleep too long!” Sorrel said.

“You were sleeping at last. You didn’t even flinch when I wet you down.”

“It’s passed 1200 hours. The sun didn’t come in?”

“No,” Bibi said. “The rays came about halfway down the tank, but we were still in shade. We’ve been lucky.”

“You sleep now,” Sorrel said. She dipped her scarf into the puddle and wondered how far down the concrete floor was. The silt in the water was slimy, which meant tiny plants grew in it, which meant it had been there for a while. Why hadn’t it evaporated? Maybe the old stream still ran, but underground?

That would be worth finding out.

She thought about a river, a real river, with cold, fresh, clean water flowing over stones, making deep, blue pools and Immersion Zones which brought a choice of exile from the city, or death by drowning.

What had this place been like before the Convergence? There would have been big trees, streams, a bridge, a road, which cars would have driven on, going up into the hills, to do what? What had been the purpose of the water tank? She sat, leaning against the tank, and tried to figure it out. The stream had flowed from mountains to plain, joining other streams and tributaries, making a bigger river, on its way to the sea. People had built the tank to store water from the stream, but then what? The severed pipe must have taken the water somewhere, to houses, to the old reservoir, perhaps. She had read about the reservoir that used to serve Bana before the desalination plant was built. It had broken away in the rain bomb of ’67 and wiped out a string of settlements of several hundred people. There were no reservoirs anymore – nothing could stand up to the force of the rain bombs – when an entire year’s worth of rain could fall in a few days. She was beginning to feel like a ghost. She ran her hands over her head – they would soon need to take out the razor. Sorrel wished she had thought to pack a mirror. In their rush to get into the water tank they had not left the charger outside in the sun so the PlAK hadn’t been recharged. There was nothing to do but sit and wait for nightfall.