Blue had no choice now. He too shouted, a meaningless yell of battle fury, and rolled in after Seamus, aware of bodies coming with him.

The place was too big to take in in one go. A huge warehouse filled with white cardboard boxes, skylights in the roof letting in some light. Lamps and candles dotted about, giving off the orange glow. Far off that sound, a beat, definitely music.

But no movement.

No sign of any monsters. No sign of anything living. Nothing to fear.

No. There. Behind some boxes. A white face. Watching. Black eyes. And then it was gone. Too quick to see if it was human. And then another. Higher up. Peering down at them. Perhaps a reptile, with wide-set eyes, fishlike. But twisted. Unbalanced.

What were they?

He was looking around frantically now. Trying to spot if there were any more of them. Ten, Seamus had said, but he hadn’t been sure.

‘There’s one!’ It was Seamus who had shouted. He was striding down towards a corner where two aisles met. The kids went with him, but holding back, letting him take the lead.

When they reached the corner they saw what he’d been following. It was scurrying away from them, but none of them could have said what it was. Human. Animal. Insect …

It moved surprisingly fast for such a weirdly shaped creature. Pulling itself along by its arms, which were long and spiderlike, the elbows pushed forward, the backs of its hands flat on the floor, palms upwards, long, thin fingers waving in the air, so that it was ‘walking’ on the bones at the back of its wrists. Its body was fat and bloated, its belly scraping along the concrete with a dry rustling sound, and there were two tiny shrivelled legs dragging along behind. The vertebrae that ran down its back stuck out like the plates along the back of a dinosaur. It was hairless, and on the sides of its neck were two big bulges, like inflated air sacs.

‘Got the bastard!’ Seamus yelled, raising his spear.

Now Blue saw that the thing was wearing some sort of clothing around its waist, a skirt or a kilt, made of leather. He felt as if he was in a strange dream, trying, and failing, to make sense of what he was seeing.

Then several things happened at once. When it heard Seamus’s shout the creature stopped and turned, just as Blue caught sight, on the edge of his vision, of another one, hiding in the shadows. A female. Impossibly thin with a head like a ball, very big eyes and a tiny mouth. Her head was so large and her body so stretched and skinny she looked like a matchstick drawing, a child’s picture of a person.

Seamus twisted, one arm forward, the other pulled back ready to throw his spear.

Blue saw the first creature’s frightened face.