It was dusk before her mother opened her eyes. “Time to be on our way,” she said. Sorrel found herself reluctant to leave. The tank felt safe – cooler than ambient and safe from ferals. She climbed onto the old cover and peered out, flinching from the glare of the retreating sun. When had the blaze of sunsets she knew only from the Literature module ceased? When had daylight started to end in this ominous, slow erasure?

“Come,” Bibi said. “Untie the rope and stow it. Look around, make sure we’re not leaving anything. You go first.”

“So what are we going to do? Follow the stream bed like we planned? Or look for the cable car line?”

“The columns,” Bibi said. “Steeper but more direct.”

“Direct to where?”

“To high up. Remember we saw them on the PlAK?” Her mother seemed rested and stronger. “Don’t climb with the backpack. Give me yours and I’ll send them both over.”

Sorrel pulled herself over the edge of the tank and dropped to the ground. She almost twisted her ankle and thought how easily this journey could end in disaster. “Send the packs,” she called, hoping she would be able to get herself out of the tank. It took a few tries, but Bibi made it.

Using the weak light of the PlAK, they searched for the metal columns that they’d seen. The searchlight caught the first column and they walked over to it. “Can you see the next one without the light?” Bibi said.

Sorrel narrowed her eyes and looked. “Yes, just.”

“Turn off the PlAK then. It needs charging. Let’s go.”

Sorrel counted in her head as they passed the columns. She wished she knew how many were ahead. She wished she knew exactly where they were going. How would they find other people? Perhaps once they were high enough and found a good place to stay, they could look around for the signs of others. What would a good place look like? Caves had advantages but could collapse in earthquakes and could easily be turned into a trap by ferals. Maybe this was a reckless and doomed journey. Maybe moving was all that was left to people. Her sore hands burned, and her muscles ached. She leaned against the straps of her pack and plodded upwards in the darkness.

The time between towers grew longer, although they were evenly spaced. Sorrel realised they must have slowed down. She wished she could see what was behind them to assess how high they were, but it was too dark.

Two hours into the climb, Bibi sat heavily on a rock.

“Rest, Bibi,” Sorrel said. “I’ll look around for a place to shelter. I don’t know if we can walk the whole night. It’s too steep. Drink some water. Rest. I’ll soon be back.”