Albert could hear it too. A faint, tinny sound, like metal scraping against metal, echoing down the tunnel, around innumerable passages and twists in the metal, bouncing off the walls of the pipe, inexorably advancing towards them.

Ollie stood up, the hand holding the gun hanging easily down by his side. ‘Larry’s on the move again. You boys are armed, aren’t you? All right, let’s get to work.’

‘Are you crazy?’ demanded Colby, holding his blaster against his chest. ‘These popguns won’t do anything to them!’

‘Perhaps not,’ agreed the fat man, ‘but that’s not to say they won’t do anything to anything else.’

The scraping metallic sound was getting louder and louder.

Ollie moved back into the tunnel behind them, where the sound was coming from. His gaze shifted upwards towards the ceiling. He stepped back into the cavern, a broad smile spreading slowly across his face. ‘Gentlemen, I think it is time, to, as they say, bring the roof down.’

Colby stared at him blankly for a moment, then a look of understanding crossed his features. ‘I’ll take the left tunnel. Who’s got the other one? You, Kieran? All right! Quickly now!’

They raced across the cavern, one blaster-toting man running across towards the tunnel on the right, Colby, to one of the two on the left, still shouting instructions.

‘Aim at the roof! Inside the pipe so you don’t bring the cave down!’

‘Sharp lads,’ remarked Ollie to nobody in particular. He lifted his gun, the metal glinting eerily in the phosphorescent light. ‘Now if you’ll excuse me for a moment.’

The scraping sound was almost deafening now, roaring down the passageway at them, death speeding towards them on artificial feet. He heard another sound from his left, sharper, a shot ringing out. Then another one, from the other side of the cavern this time. Then some more. Colby and his companion had begun attacking the roofs of their tunnels.

Ollie turned, sauntering into the tunnel. ‘Ah,’ Albert heard him say, his voice echoing strangely in the closed confines of the pipe. ‘Here comes larry!’

Then he began firing at the roof.

It was over surprisingly quickly. There was a twisting, tearing sound, then another—this one screeching, almost heartrending as if the metal itself were alive, screaming out, begging for mercy—and moments later there was a thunderous crash. They stepped back as angry clouds of dust streamed into the cavern from the tunnel, reaching out for them with malevolent hands. Behind them, they heard another crash. Looking around, they saw more dust. Colby had succeeded in bringing his tunnel down, too. Turning back and peering through the thick brown haze in front of them, they saw Ollie, now also clad in a generous coating of the same dust. For once, he wasn’t smiling.