None of this mattered. Rio was missing.

He hesitated, there in the unshaded sunshine. Enclosure underground would be even worse than in the Poulson house, because his primary defence, stepping out of any danger, wouldn’t be available to him. He nearly backed away. But Rio … Carried all the way from Datum Earth as a pup by a trader, she was a Bernese mountain dog, bred, it was said, to pull carts laden with cheese. She was strong, with good lungs, but slow.

She was Nikos’s dog. If he had to climb down into this hole he would.

He got down on his hands and knees, cautiously, and peered into the hole, through the broken plank. All he saw was darkness, even when he shone in his flashlight.

‘Rio!’

At first he heard nothing at all, not even an echo. Then came a bark, undoubtedly Rio’s, from out of the hole – but it sounded remarkably far off – not like it was from a dog trapped just a few feet down. ‘Rio! Rio! …’

And then he heard another sound. A kind of scraping, almost a whispering, like some huge insect. It seemed to move away, as if burrowing deeper down. All the legends and scare stories in his head came bubbling back to the surface. Again, he almost backed off. But his dog was down there.

Feverishly he began to pull away the remaining planks, carelessly tipping dirt into the hole. ‘Rio! Here, girl! Rio! …’

The pit he revealed was only maybe eight feet deep, crudely cut into loose-packed earth. He dangled over the edge, made sure he could scramble back up the sides before committing himself, then he dropped down to the bottom.

He looked around. If this had been intended to be a cellar it wasn’t much of one, the walls bare earth, the floor still showing the spade marks left by the original digger and not smoothed off. It was just a hole in the ground, hastily cut and more hastily concealed. And there was no sign of his dog.

It was pretty clear where Rio had gone, though. There was a breach in one wall, down near the floor.

Making sure he had his pocket knife to hand, Nikos got down on hands and knees, and found himself looking into a kind of tunnel in the earth. It wasn’t too wide, just a few feet, but it was a lot more smoothly cut than the aborted cellar, with a circular profile and smooth walls. And, he saw, sweeping his flashlight, it sloped down at a fairly steep angle. Down into darkness, beyond the reach of his light. What could have made this? Some kind of burrowing animal, maybe? There were furballs that lived underground, and his mind conjured up a vision of a squirrel-mole the size of a human, with claws on its big digging paws the size of spades. It would be like a kobold, he thought, a human-sized mole-like humanoid that sometimes came by, trying to trade. But he remembered that peculiar rustling, that whispering, scraping noise, like no sound a furball would make, or even a kobold.

Then, in the furthest distance, he heard another bark, a frightened yelp.

He let instinct take over. ‘Coming, girl! Just you wait for Nikos!’

He took his flashlight in his mouth, entered the tunnel on all fours, and began to crawl down the slope. Under his hands and knees there was only dirt, smoothed over and close-packed. Behind him the disc of daylight receded, while ahead of him the light of the flash showed another opening at the end of the tunnel, a neat circle that let out into a still deeper dark. Being shut up in this tunnel was scary, and the Stepper box at his belt made it awkward to move. He’d have to back up to get out of here, for he’d have trouble turning round. But he pushed on.

He travelled maybe twenty feet, he figured, a steady descent down into the dark.

Then the slanting shaft ended in an opening to a much larger chamber. Still on his hands and knees, he cautiously peered out, waving his light. His flash picked up a roof and floor, both smoothly worked, maybe ten feet apart, and pillars, like remnants of cutaway dirt or bedrock, regularly placed. He couldn’t see any walls, to either side or ahead; his flash wouldn’t reach that far. He was evidently entering a much more expansive space, wide and deep.

So much for his ideas about squirrel-moles. What the hell was all this?

It reminded him of what he’d read, in his mother’s irregular school classes, about mining back on the Low Earths. He knew there was a seam of iron ore around here that the founders had plundered when the Poulsons had built their forge – the rich seam, unique to this particular world, was one reason they’d settled here. But he’d seen the size of that home-built forge, and the handfuls of nails and such they’d made, the few horseshoes for the exotic-sounding animals they’d meant to import here some day but had never gotten around to (Nikos had never seen a horse). They could never have dug all this out in such a short time, and there would have been no need anyhow. But if not them—

The face appeared in front of him.

Face: that was one word for it, a mask that was vaguely the shape of a human face, one side covered by silvery metal, the other even worse, sculpted out of what looked like the black shiny stuff God made beetles out of, as his father might have said. But it was a definite face, mounted on a tiny-looking head that tilted on a narrow neck.

It almost looked curious. Inspecting him, that odd head tilting. Curious. Alive!

The delayed shock hit him. He screamed, and the noise echoed loudly from that big open chamber beyond. He tried to back up, but he lost his hold on the tunnel’s sloping floor, and he slid forward, and tumbled out of the shaft—

Right into the arms of the silver-beetle creature. Arms? Did it have arms? He felt cold metal under his back, his legs. He yelled and struggled, and was released.

He hit the ground, a drop of only a few feet, but it knocked the wind out of him, and he dropped his flashlight. He rolled to his feet quickly, but in the dark, with the fallen flash giving only a sliver of light, he felt turned around, disoriented.

He saw the beetle thing roll on to its belly and scuttle away, perhaps as alarmed as he was. It looked human-sized, but like a beetle or a locust in its shape and the way it moved and in the shiny black hardness of its body, its multiple limbs.

And he saw, he heard, more beetle creatures approach. He grabbed the flashlight off the floor and swung it around.

They were coming at him from all sides, crawling along the ground, like an ant swarm but much larger, more monstrous, and the way those shiny black carapaces were laced with metal, stuff that had been made, was somehow even more horrific. When he pointed the light at one it flinched back as if dazzled, but from every other direction they kept on approaching. And when they got close they started rearing up, and he saw soft bellies exposed, with pale grey pods clinging to greenish flesh, like blisters.

Then one of them rose up right before him. He saw a half-face silver mask just like the first he’d encountered – maybe it actually was the first, he had no way of distinguishing them one from another – and a kind of tentacle, thread-like, silvery, reached out towards him.

He tried to stay still. But when the pseudopod touched him, cold metal on warm flesh, Nikos’s nerve broke.

He ran forward, yelling, waving his flashlight, pushing through rustling bodies that tipped and scrambled to get out of his way. He didn’t get very far before he tripped over something and fell on to a hard, compacted floor. Again he dropped the flash, and he had moments of panic in the shifting shadows of the dark before he got it back, moments when he could hear them shifting and whispering and scraping all around him. He had no idea which way the wall was, and the shaft he’d emerged from. Panic rose again, choking him.

And once more one of the beetle things reached out with a squirming silvery tentacle-limb. Without thinking Nikos lashed out with the flashlight. He caught the thing on the dark side of its face, avoiding the metal mask. The black shell cracked, and a kind of pulp, green and foul-smelling, leaked out. As the beetle fell back, another made to grab its wounded companion. But in doing so it came close to Nikos, and again he swung the flashlight—