"That's a good question, considering the fact that my family just moved here. The house that we live in now used to belong to my great-aunt who died recently, and that was just the first of many things that compelled our mother to drag us out here in the middle of the school year. When my twin brother, Alistair, and I were just tykes, we'd visit my aunt during the summer, since Scottish summers are just rain and more rain. It became a game for us to run around these woods, which are very close to her...our...propert y. One day we stumbled across this cave system...literally, we stumbled. There is a big hole in the roof of the cave, towards the back, and Alistair tripped on a tree root and fell right into it. I climbed down after him and helped him limp back home. That night I snuck out of the house with my zippo, mag-lite, canteen, switch-knife, you name it: if it's necessary to woodland survival, I had it with me. After getting caught in a bog once, back home, we learned never to be without a source of light and heat, or a way to sustain ourselves and get out of sticky situations. Anyway, I climbed down into the cave and lit a big fire inside to clear out the brush that had taken it over. I climbed out, covered the hole with a tarp, and looked for the smoke to escape in other places. I found nearly twenty separate entrances into the system. That explains the ashes on the floor, which I decided to keep, since they show me if anyone has been here other than me."
I gestured to the fine grey powder that drifted around our feet.
"I think that the cavern system covers two or three miles at just-below-ground level, but I've found deeper tunnels that might go on even farther. This particular section of the cave branches into three tunnels, and one of them is a dead-end that I use to store emergency supplies, in the event that I feel like running away from home. I like to always have a few contingency plans, back-ups, if you know what I mean. The second leads to the other tunnels, and the third, to the far right, goes at least a mile underground, if you follow it. It leads to my 'bathroom' here: a hot spring fed by a subterranean river and heated by the local seismic activity. If you need to wash up, I have some soap and shampoo down there, stuff like that. Just be careful not to drink the water. It's harmless on your skin, actually killing germs and speeding healing, but you don't want to swallow sulpher and the minerals that come out of the hot-vents. Farther into the same tunnel is the only place where the river meets the surface, aside from the spring. It works well as a latrine and garbage disposal, carrying away any wastes. I think that five or six people could probably stay down here indefinitely, but it isn't nearly as comfortable as a proper house."
I indicated the rocks that we were using for chairs.
"Aside from the two of us, only my brother knows this place exists, but he never expressed the kind of interest in it that I did, so even he won't disturb us here. I've been careful not to leave any clear signs of my presence here, and I hide all my supplies inside the natural rock formations and cracks in the walls, which keep the passing hikers from noticing, for instance, the shiny black mag-lite. The brush across the main entrance is also helpful in that."
I nodded in the direction of the entrance, so thoroughly hidden that no light could escape.
"I've only followed one of the deep tunnels to its end...well, actually, it has two 'ends', but Al was the one that found the end of the other fork, back when he was still interested. Based on my calculations of the distances, one opens up right underneath the shopping mall in town, where it goes up for a little way, and then stops suddenly. I've been tempted to dig it open, because I KNOW that it hits the surface within a few feet, but I've never had the time or the tools. The other end is a huge cavern, approximately the size of a ball stadium, right under where my school SHOULD be. That one has five or six offshoots, but they are claustrophobically tight. That's about it, as far as I know. Do you have any more questions?"
(Guys, just so you know, my 'cave system' is attached to what USED to be the Yeerk pool under the town, which got mostly-filled-in after the Pool Ship blasted it to smithereens. Those tunnels that I mentioned are part of that original system, but the parts that 'I' use are naturally occurring, not Yeerk-made.)