The Quantum Thief

He walks down the long, winding steps of the Inverted Tower with the other mourners, in silence, eyes aching from a sleepless night. The Tower hangs from the belly of the city like a crystal teat. They can see the city’s shadow for the whole journey, the slow rhythmic rise and fall of the city’s legs. Above, the platforms of the city shift and interlock as the city optimises its weight distribution with each step. Everything is tinted with orange dust. The light of Phobos – a former moon, now turned into a star by the tiny singularity inside it – gives the world an odd, timeless, twilight feel.

There are few mourners this morning. Isidore walks behind a black man whose back is bent by the weight of his quicksuit.

Every now and then, they pass a platform manned by a silent, masked Resurrection Man. The movements of the Quiet below are obscured by the dust cloud, but the phoboi walls are visible. The ramparts stretch towards the horizon and define the city’s planned route. They contain the trail of new life behind the city, a paintbrush streak of synthbio fields and terraforming machinery. Like its brothers and sisters, the city tries to paint Mars green again. But in the end, the phoboi always come.

At the bottom of the Tower, there are elevators waiting. Resurrection Men give them fireflies to follow, accompanied by stern instructions to make it back by noon. One of them helps Isidore don his quicksuit, Oubliette make, with modern programmable materials but with far too much design effort spent on it, brass and leather, so that it looks like an ancient diving suit. The gloves are clumsy and it is difficult to hold on to the bouquet of flowers he has brought. They crowd into the elevator through an airlock – a simple platform suspended from nanofilament – and descend through the orange mist, swinging back and forth with the city’s motion. And then they are on the surface, slow-moving figures in bell-like helmets, each following a firefly.

The vast mass of the city looms above like a second, heavier sky, with fractures and seams where the different platforms meet, moving and shifting slowly like clockwork. From this vantage point, the legs – a forest of multi-jointed shafts – seem too frail to hold it up. The thought of a falling sky makes Isidore uncomfortable, and after a while, he decides to focus his gaze on the firefly.

The sand beneath his feet is beaten hard by legs and tracks and other locomotion methods of the Quiet. They are everywhere here, tiny ones that scatter to make way for his feet, as if he were a giant City striding across their landscape. There are terraforming Quiet, bigger than a man, moving in herds, toiling on the algae and regolith. An Atlas Quiet strides past, making the ground shake, a six-limbed caterpillar larger than a skyscraper, on its way to correct the balance of a city leg or to make sure the ground is safe when it completes its arc. He sees an air factory Quiet in the distance, a plant on tracks that is like a small city in itself, with swarms of flying Quiet around it. But the firefly does not let him linger. It leads him across the shadow of the city at a rapid pace, up and ahead where his father is helping to build phoboi ramparts.

His father is ten metres tall, with an elongated insect body. He burrows into the Martian regolith with a grinding noise, pulling up powdered rock through a chemical processing system, mixing it with synthbio bacteria, turning it into a construction material for the wall. His dozen limbs – spindly and fast-moving – shape the material flow from his beaklike mouth, laying down the wall, layer by layer. His carapace has a metallic hue that looks rusty in the orange light. There is a dent on his side, with another limb bud growing from it; a memory of a recent phoboi battle.

He labours side by side with a hundred others; some of them climb on top of each other, making the wall taller and taller. But his father’s section of the wall looks different. It is full of faces, reliefs and shapes. A lot of them are almost immediately shattered by the smaller mechanic Quiet who come and install the wall’s weaponry. But Isidore’s father does not seem to care.

‘Father,’ Isidore says.

The Quiet interrupts his work and turns to Isidore slowly. His metal carapace snaps and groans as it cools. The usual fear chills Isidore, the awareness that he is going to be inside a body like that one day. His father looms above him in the orange dust like a bladed tree, the mechanisms of his hands slowly spinning down.

‘I brought you some flowers,’ Isidore says. The bouquet is full of his father’s favourites, tall Argyre lilies, and he places it on the ground carefully. His father picks it up gently, with exaggerated care. His blades spin again for an instant, and the spidery shaper limbs dance. The Quiet places a tiny statue in front of Isidore, made from the dark wall material, a man making a bow and smiling.

‘You’re welcome,’ Isidore says.