“Not that easy to see from above. But if we follow the river and climb up here –” she pointed – “I think there’s a good chance of caves along this stretch of the cliff. I can’t tell you about food, though.”

“The army camp?”

“Too hazy. A wall right around, though. And we know the Toplanders are dangerous.”

“What else?”

“Closest small town is here, in the next valley over, quite far down and it looks really small. Will be difficult to get down and back, assuming we find a cave in the cliff I showed you. But I think there’s a small dump on the outskirts that maybe no one has found yet – see? This even looks like a plastic water tank.”

“You’re right. Maybe there’s food in that valley too.”

Sorrel moved the cursor and the world the satellite saw, spun and pixelated. “I was just about to look at the bigger picture.”

Caroni sat quietly as Sorrel trolled the satellites she could find; she knew them by name: Andromeda, Vega, Aldebaran, and the servers: Range, Fabros, Switch, EnGen, skimming over the ocean with the eyes of a drone, the sea still dotted with the rusting, buckled oil rigs of the fossil-fuel centuries. Finally, she found a town on the blue water of the Ocean of Atlantis, close enough to Bajacu to make an evacuation feasible. No name was given, but it sat where a wide, curving river valley had once met the new edge of the sea. She zoomed in.

The buildings of the town were floating. “That’s how they survived,” she said to Caroni. “They built houseboats and shopboats.”

“The buildings rose with the sea,” Caroni agreed. “Place looks military, all those camouflage colours.”

Then they both saw the evacuation boats, big ones, manystoreyed. Military vehicles on land, perhaps to keep order. Lines of people. How would such vessels be provisioned? Surely there was not that much food in all the world. How were they powered? How long would the journey take? How would they dock? Or would the Northerners simply moor the boats to the island and live aboard? One vessel had what looked like a small helicopter on deck. They all had lifeboats. Were those respirators on the faces of the people in the lines?

Sorrel panned west and saw the smoke of the fires. If the wind had been in a different direction, she wouldn’t have seen the town. On a whim, she changed satellites to look at the Ocean of Atlantis. The screen froze and for a few minutes showed only a few clouds over the vast, crinkled sea. Then, just off the coast of Africa, Sorrel saw a broad swathe of dust in the shape of a teardrop. “Look. A dust storm, coming our way,” she said. “When it gets here, we won’t be able to travel.”

“How many days?”

“I don’t know for sure. Depends on the wind. Maybe three or four.”