Elias was his only friend. Elias was born into the caravan, and knew no other life but that of the endless march. His life was bound by destinations: Cairo, Oman, Neom. He was born in transit and would, he told Saleh cheerfully, die the same way. Early on their travels they had come under sudden attack from a herd of wild drones. The khans returned fire but one of the flying machines hit an elderly tracker and he died. It was done in almost complete silence and over before anyone could properly react. The caravaners mourned the loss, and then they left the body where it lay and moved on, and the desert alone claimed the old tracker’s corpse.

Saleh longed for the sea again and he dreamed of the stars. He lost his sense of time. The days began early. The elephants trudged through dust and sand. Robots slithered underfoot. The other children played games Saleh never joined for he was no longer a child. He was the last of his line. He could have been a caravaner, only he had begun to loathe the wadis and the mountains, the dry wind and the wild machines and that sense that the desert was there long before people, and would remain long after the people were gone.

He wanted to go to the Valles Marineris! He wanted to smell hot humid trees, to feel the falling rain. He wanted to taste a Malay apple and watch the ice comets as they fell.

He wanted to be anywhere but where he was.

Day followed night and the caravan pushed through the desert on its slow winding path. Until one day they came to an oasis that had no name and was on no map, and there they stopped for a while.

The elephants luxuriated in the fresh water. The children ran shrieking through puddles. Elias and Saleh sat under a tree and ate dates.

“It is a good day,” Elias said.

“How can you tell?” Saleh said.

Elias smiled. “It will not be long before we reach the sea again,” he said kindly.

Saleh nodded. But he still felt so alone.

Someone whistled. The sound repeated, was amplified throughout the camp. Saleh saw the scouts move cautiously.

“There,” Elias said. Saleh followed his pointing finger. High up on the mountainside he saw a human figure. It stood and watched the oasis and then, swiftly, it was gone.

More whistles. Elias signalled to a scout who signalled back but shook her head. Elias signalled again, more forcefully. This time there was a reluctant nod.

“Come on,” Elias said.

“Where are we going?”

“You ask a lot of questions,” Elias said. “Bring the dates.”

Saleh followed him. Elias wore his goggles and his rig. He was not noded at birth but could access the caravanserai’s machines.

“I am the speaker,” Elias said, “so I will go. And you are my friend, so you will come with me, too.”