It crept at bizarre angles between the walls of the terrace, tight and close, sending the sound of his breath and the clanking of the monkeys’ bouncing into Isaac’s ears. His hands and knees ached from the crushing pressure of the sharp stone-shards under him. Isaac estimated that they were moving back through the terraced houses. They were shuffling downwards, and Isaac remembered how the curve of the dome had decapitated the houses at a lower and lower point as they approached the glass. The closer the houses were to the edge of the dome, he realized, the lower they would be, the more filled with old wreckage.

They were shuffling their way along the little stub of the street, towards the glass dome, down through deserted floors in an interstitial burrow. Isaac shivered for a moment in the dark. He was sweating from heat and from fear. He was terribly frightened. He had seen the slake-moths. He had seen them feed. He knew what might be before them in the depths of this wedge of rubble.

After a short time of crawling Isaac felt a moment’s drag on him, then a release. He had reached the full extent of his piping, and Yagharek had let it go to drag behind him.

Isaac did not speak. He could hear Shadrach behind him, breathing deeply and grunting. The two men could not move more than five feet apart, because the wires connected their helmets to a single motor.

Isaac threw up his face and swung it around him, desperately searching for light.

The monkey-constructs swung their way up. Every few moments, one would momentarily turn on the lights in its eyes, and for a minuscule fraction of a second, Isaac would see a stark crawlway of littered brick and the metal gleam of the constructs’ bodies. Then the lights would go out. Isaac would try to negotiate by the ghost image that slowly ebbed from his eyes.

In the absolute dark, it was easy to sense the slightest glimmer. Isaac knew that he was crawling towards a source of light when he looked up and saw the grey outline of the tunnel ahead. Something pressed Isaac’s chest. He started massively, then recognized the pewter fingers and dark bulk of a construct. Isaac hissed to Shadrach to stop.

The construct gesticulated to Isaac with exaggerated jerky gestures. It pointed forward, towards its two fellows that hovered at the edge of the visible shaft, where the tunnel turned a sharp corner upwards.

Isaac indicated that Shadrach should wait. Then he crept forward at an almost motionless pace. Glacial dread was beginning to creep through his system, from the stomach out. He breathed deep and slow. He shifted his feet slowly, inching along, until he felt his skin prickle as it emerged into a shaft of faint light.