“I’m going to have to ask you to come with us,” he told the robot.

“No,” the robot said.

It kept digging.

“What do you mean, no?” Habib said. “We’re the shurta!”

“You are city cops for rent,” the robot said. “No offence.”

“You’re just a robot!” Habib said.

The robot dug.

Laila pulled out a long tube. Grenade launcher, sometimes useful against the smaller UXOs. The ground shook. Nasir knew the worm was getting closer. The robot dug below, and suddenly its spade hit something in the sand and the sound of metal on metal chimed in the air. Nasir saw three large figures move ahead in the darkness, under the stars. Laila fired the launcher. Two explosions, one after the other, and one of the UXOs, the eight-legged hyena, blew up. Hot wind and sand and the smell of metal hit them.

Habib said, “They’re behind us!”

Nasir turned too slow. The other two UXOs stood there. Behind them came the worm, he could see the groove it made in the earth as it moved.

“Don’t shoot,” Nasir said. The other two UXOs came and squatted on the sand. The worm slowed down then. It reared its head out of the sand, something vast and strange and yet a little like an ant lion. It, too, stared at the hole.

“What are they doing?” Laila said.

“I don’t know,” Nasir said.

He risked a look at the hole. The robot was digging, but it had let go of the spade and now cleared away sand gently with its fingers. Nasir saw how old the robot was then, rusted and patched. Its fingers moved with care and something gold flashed in the dirt.

“Stay back,” Habib said. “Stay back!”

“They’re not doing anything,” Laila said. “They’re just . . . standing there.”

Nasir stared. The worm—the Vermes arenae sinaitici gigantes, to give it its full scientific name—rose above them but it didn’t move and its body was stationary in the sand. The UXOs, similarly, remained in place, cameras or eyestalks trained on the hole as though anticipating—what?

“Put it down,” Nasir said. He spoke softly. This tableau could not last: he knew it, Habib knew it, the UXOs must have known it. Something had to break the equilibrium and once that broke, well, UXOs blew up and sandworms blew hot, as the saying went, and the winds of the desert blew the soft skin and flesh until only the bones remained of those who were lost.

“Get back in the car. Habib, get back in the car!”

Down in the hole the robot dug. Gold flashed again, and was that an arm in the sand? The robot pulled, gently, carefully. Nasir saw a golden shoulder, a torso being pulled.

“They do not like it,” the robot said, not looking up. It said it conversationally.

“They don’t like what you are doing?” Nasir said.

“That, too.”