Tunnels

frown.

'What's up, Will?'

'The props farther into the tunnel were completely sound — I gave them a once-over before we left last time. And there hasn't been any rain recently, has there?'

'No, I don't think so,' Chester replied.

'No, and this dirt doesn't feel nearly damp enough to cause the roof to slip in — there's no more moisture than you'd expect. But the weirdest thing is all this.' He reached down, plucked out a chunk of stone from the pile, and tossed it over to Chester, who caught it and examined it with a bewildered expression.

'I'm sorry, I don't understand. What's important about this?'

'It's limestone. This infill has bits of limestone in it. Feel the surface of the rock. It's chalky — totally the wrong texture for sandstone. That's particulate.'

'Particulate?' Chester asked.

'Yes, much more grainy. Hang on, let me check to make sure I'm right,' Will said as he produced his penknife and, folding out the largest blade, used it to pick at the clean face of another piece of the rock, talking the whole time. 'You see, they're both sedimentary rocks, and they look pretty much the same. Sometimes it's quite hard to tell the difference. The tests you can use are to dropacid on it — it makes limestone fizz — or look at it with a magnifying glass to see the coarser quartz grains you only get in sandstone. But this is the best method by far. Here we go,' Will announced as he took a minute flake of the stone he'd pried from the sample and, to Chester's amazement, slipped it off the blade and into his mouth. The he began to nibble it between his front teeth.

'What are you doing, Will?'

'Mmmm,' Will replied thoughtfully, still grinding it. 'Yes, I'm pretty sure this is limestone… You see, it breaks down into a smooth paste… If it was sandstone, it'd be crunchier, and even squeak a little as I bit it.'

Chester winced as he heard the sounds coming from his friend's mouth. 'Are you serious? Doesn't that crack your teeth?'

'Hasn't yet.' Will grinned. He reached into his mouth to reposition the flake and chewed on it for a little longer. 'Definitely limestone,' he finally decreed, spitting out what was left of the flake of rock. 'Want a taste?'

'No, I'm fine, really,' Chester replied without a moment's hesitation. 'Thanks anyway.'

Will waved his hand in the direction of the roof over the cave-in. 'I don't believe there'd be a deposit — an isolated pocket of limestone — anywhere near here. I know the geology of this area pretty well.'

'So what are you getting at?' Chester asked with a frown. 'Someone came down here and blocked up the tunnel with all this stuff?'

'Yes… no… oh, I don't know,' Will said, kicking the edge of the huge heap in frustration. 'All I do know is that there's something very funny about all this.'

'It might've been one of the gangs. Could it be the Clan?' Chester suggested, adding, 'Or maybe even the Click?'

'No, that's not likely,' Will said, turning to survey the tunnel behind him. 'There'd be other signs that they'd been here. And why would they just block up this tunnel? You know what they're like — they would've wrecked the whole excavation. No, it doesn't make sense,' he said, bemused.

'No,' Chester echoed.

'But whoever it was, they really didn't want us to go back in there, did they?'

* * * * *

Rebecca was in the kitchen doing her homework when Will returned home. He was just slotting his shovel into the umbrella stand and hanging his yellow hard hat on the end of it when she called to him from around the corner.

'You're back early.'

'Yeah, we had some trouble in one of the tunnels and I couldn't be bothered to do any digging,' he said as he slumped down dejectedly in the chair on the opposite side of the table.

'No digging?' Rebecca said with mock concern. 'Things must be worse than I thought!'

'We had a roof fall in.'

'Oh, right…,' she said remotely.

'I can't figure out what happened. It couldn't be seepage, and the really odd thing was that the infill…,' he trailed off as Rebecca rose from the table and busied herself at the kitchen sink, clearly not listening to a word he was saying. This didn't bother Will unduly; he was used to being ignored. He wearily rested his head in his hands for a moment, but then raised it with a start as something occurred to him.

'You don't think he's in trouble down there, do you?' he said.

'Who?' Rebecca asked as she rinsed out a saucepan.

'Dad. Because it's been so quiet, we've all assumed he's gone somewhere, but he could still be in the cellar. If he hasn't eaten for two whole days, he might have collapsed.' Will rose from his chair. 'I'm going to take a look,' he said decisively to Rebecca's back.

'Can't do that. No way,' she said, spinning around to face him. 'You know he doesn't let us go down there without him.'

'I'm going to get the spare key.' With that, Will hurried out of the room, leaving Rebecca standing by the sink, clenching and unclenching her fists in her yellow rubber gloves.

He reappeared seconds later. 'Well, are you coming or not?'

Rebecca made no move to follow him, turning her head to look out the kitchen window as if mulling something over.

'Come on!' A flash of anger suffused Will's face.

'Fine… whatever,' she agreed as she seemed to come to again, snapping off her gloves and placing them very precisely on the drainer at the side of the sink.

They went to the cellar door and unlocked it very quietly, so their mother wouldn't hear. They didn't need to worry, though, since the sound of a barrage of gunfire was coming thick and fast from inside the living room.

Will turned on the light and they descended the varnished oak stairs he had helped his father fix into place. As they stood on the gray-painted concrete floor, they both looked around in silence. There was no sign of Dr. Burrows. The room was crammed with his belongings, but nothing was that different from the last time Will had seen it. His father's extensive library covered two walls, and on another were shelves housing his «personal» finds, including a railwayman's lamp, the ticket machine from the disused railway station, and a careful arrangement of primitive little clay heads with clumsy features. Against the fourth wall stood a workbench, on which his computer sat, with a half-consumed candy bar in front of it.

As Will surveyed the scene, the only thing that seemed out of place was a wheelbarrow filled with dirt and small rocks by the door to the garden.

'I wonder what that's doing in here,' he said.

Rebecca shrugged.

'It's funny… I saw him taking a load out to the Common,' Will went on.

'When was that?' Rebecca asked, frowning thoughtfully.

'It was a couple of weeks ago… in the middle of the night. I suppose he could have brought this in for analysis or something.' He reached into the wheelbarrow, took some of the loose soil into his palm, and examined it closely, rolling it around with his index finger. Then he held it up to his nose and breathed in deeply. 'High clay content,' he pronounced and sunk both hands deep into the soil, lifting out two large fistfuls, which he squeezed and then released, sprinkling them slowly back into the barrow. He turned to Rebecca with a quizzical expression.

'What?' she said impatiently.

'I was just wondering where this could have come from,' he said. 'It's…'

'What are you talking about? He's obviously not here, and none of this is going to help us find him!' Rebecca said with such unnecessary vehemence that Will was left speechless. 'Come on, let's go back upstairs,' she urged him. Not waiting for Will to respond, she stomped up the wooden steps, leaving him alone in the cellar.

'Women!' Will muttered, echoing a sentiment his father often imparted to him. 'Never know where you are with them!' Rebecca in particular had always been a total mystery to Will — he couldn't decide whether she said the things she did on a whim, or if there was really something much deeper and more complex going on inside that