Descending slowly, testing each foothold firmly before settling my weight on it. Coming down three abreast, me in the middle, Loch on the left, Bill-E on the right. Loch complains several times about not having a light of his own, but Bill-E refuses to relinquish either of his torches. I've been to his house. I know that Ma and Pa Spleen keep several torches around the place, ever fearful of power cuts, determined never to be left stranded in the dark. He could have easily brought another torch for Loch. A mistake or intentional oversight? I don't enquire.

It's stuffy down here, warmer than I imagined. The air's not so bad though. I thought it would be stale and thin, but there's a good supply of it. Easy to breathe.

Part of me knows this is madness. It screams from the back of my head, reminding me of what happened last night, the face, the whispers, the throbbing today. It wants me to assert myself, demand we make for the surface, tell Dervish, leave all this for experienced potholers to explore.

But a larger part thinks it's thrilling. We're the first humans to come down here in decades. In fact, if the others are wrong and this wasn't used by Lord Sheftree, maybe we're the first people to ever find it. Maybe it will turn out to be an amazing geographical feature and we'll get to name it and be on the news. Reni would really dig being a celebrity's girlfriend.

You're an idiot, the cautious part of me huffs with disgust.

"Put a sock in it," I grunt back.

I lose track of time pretty quickly. Have we been down here ten minutes? Twenty? The hands of my watch are luminous, so I could check. But I'm not going to start fiddling around in the dark, rolling up my sleeves, leaning forward to squint. I'm keeping both hands on the rock face and all my senses focused on the climb.

I go carefully, one hold at a time. Foot-hand-foot-hand-foot-hand-foot. Bill-E and Loch are the same. We don't speak. My torch hangs from my right wrist by a strap. The light bounces off the rocks. I'd have to stop, turn around, lean back and point the light down to get a clear view of what lies beneath. But I'm not going to do that. I'm taking no chances. The thought of slipping... sliding... tumbling into the unknown...

Foot-hand-foot-hand-foot-hand-foot-ha-

I touch ground. Or a very large overhanging rock. Can't tell yet. "Wait," I call softly to the others, who are slightly higher than me. "Let me feel around a bit. I think..." I extend my foot outwards. More rock. I tap it-solid. Gently lower my other foot, still holding tight to the wall. Gradually letting my full weight shift to my feet, I release my grip and stand unsupported. The ground holds and my stomach settles.

Bringing up my torch, I shine it around and gasp.

A cave. Not the largest I've ever been in, but a reasonable size. Lots of stalactites and stalagmites. A waterfall to my right. I should have heard the noise before now, except my breath and heartbeat were heavy, muffling my hearing.

"Grubbs," Loch hisses. "Are you OK? What is it?"

"I'm fine," I whisper, then raise my voice. "It's a cave." I shine the light on the floor around my feet, making sure I've truly struck bottom. I spot the shovel which Bill-E dropped. "It's OK," I tell my friends. "You can come down."

They detach themselves from the wall and stand beside me. The light from Bill-E's torches mingles and crosses with mine and we gaze around in awed wonder.

The formations are beautiful, some of the most incredible I've ever seen. Water drips slowly from the tips of many stalactites, so this is an active cave, still growing. I recall lectures from a couple of class trips to caves. It can take thousands of years for spikes to form. Thousands more for them to alter. If I lived to be a hundred and came back here just before my death, this cave would probably look no different than it does right now.

"It's amazing," I sigh, taking a step forward, head tilted back, looking up to where the roof stretches ahead high above us. "How can this have been here all this time... hidden away... nobody knowing?"

"The world's full of places like this," Bill-E answers even though I wasn't really asking him. "We only see a fraction of what's on offer. People find new caves, mountains, rivers, all the time."

"OK," Loch says loudly, shattering the mood. "It's a lovely cave, beautiful, glorious, la-dee-da-dee-dum. But I don't see any treasure."

"Peasant!" Bill-E snarls. "This is the treasure. You couldn't buy a cave like this, not with all the gold and diamonds in the world."

"I don't want to," Loch says sourly. "What good's a damp, dirty cave? I'll settle for the gold and jewels." He looks around and spits. "If there are any."

Bill-E turns, temper fraying. I speak up quickly. "He's right, Bill-E. Not about the cave not being worth anything-it's amazing, beyond any price. But we came looking for a different sort of treasure. We should check to see if it's here. If it isn't, that doesn't matter-we'll still have found the cave. But if there's treasure too, all the better."

Bill-E relaxes. "Yeah, let's look. The cave isn't that big. If there's treasure, it shouldn't be too hard to find."

We move forward, three explorers in wonderland. Even Loch looks impressed, although he isn't blown away by the cave's beauty in the same way as Bill-E and me. We stroke the rising pillars, fingers coming away damp. In certain places the stalactites and stalagmites have grown together to form giant, solid structures which join the floor and ceiling. One is wider than the three of us put together, a monster resembling a couple of massive chimneys.

"I've never been down a cave without a guide, or in such a small group," Bill-E says after a while. "It's strange. Quiet. Peaceful."

"Hey," Loch grins. "You know my favourite bit when I'm down a cave? It's when they turn the lights out so you can see what it looks like pitch black."

"No way!" I say quickly.

"Uh-uh!" Bill-E chimes in.

"What's the matter, ladies?" Loch laughs. "Scared of the dark?"

Bill-E and I share a look. Neither of us wants to switch the torches off. But Loch's smirking goadingly.

If we don't meet his challenge, we'll never hear the end of it.

"Go on," I mutter to Bill-E. "You first."

He gulps and turns one light out, then the other.

The cave feels much smaller now, more threatening. It's probably my imagination but I believe I can sense shapes in the shadows, waiting to form fully in the darkness so they can leap forward and pounce on us unseen. My finger hovers over the switch on my torch. I'm torn between not wanting to look like a coward and not wanting to fall prey to forces of magical malevolence.

Before I can make a decision, Loch does it for me. "What a sissy," he crows, then reaches over, jams my finger down hard and jerks it backwards, quenching the light.

My heart races. My breath stops. The walls seem to grind shut around me. In a panic I try to turn the torch on, but my finger's numb from where Loch pressed down on it. I can't find the switch! I can't turn the light on! The shapes are coming! In a second or two they'll be upon us, all claws, sharp teeth and...

Bill-E switches one of his torches on. He's chuckling weakly. "That was cool."

I look around-nothing. The cave looks exactly the same as it did before. I was imagining the danger. I force a short laugh and switch my torch on, then press ahead with Bill-E and Loch. We continue exploring.

After half an hour I don't feel too hot. It's nothing to do with the temperature of the cave-it's warmer down here than it was on the surface-but with the time. I check my watch to confirm what I already know-it's night. High above, hidden from sight by the layers of rock and earth, the moon's rising, and tonight it's as full as it's ever going to be.

I get the same sick feeling as last night and the night before, only stronger, relentless. In horror movies, people sometimes don't change into werewolves unless they sight the moon-if it's hidden by clouds, or they're locked away, it doesn't affect them. But that's rot. The moon's a powerful mistress. She can reach through any wall or covering and work her wicked charms.

Bill-E and Loch are bickering about the treasure and whether or not it's here. Loch doesn't think it is-we've been around the cave a few times and found nothing-but Bill-E still insists it could be.

"You don't think Lord Sheftree would have left it lying on the floor for anyone to stumble across and walk off with, do you?" he argues. "He'd have thought about somebody finding the cave, either by digging down like we have, or maybe through some other entrance he didn't know about. He'd have hidden the treasure, stuck it out of sight, so that even if a stranger wandered in by accident, they wouldn't find it, not unless they actively searched for it."

"So where do you think it is, geniass?" Loch sneers. "We've looked everywhere. Unless it's invisible treasure, I don't think-"

"We've looked nowhere," Bill-E shouts, and his voice echoes tinnily back at us. "Some of the larger stalagmites might be hollow," he says, quieter this time. "The treasure might be buried in one of them."

"There's an awful lot of stalagmites," Loch says dubiously.

"We have time," Bill-E smiles. "And maybe it's not down here at all." He points up at the walls. "There are ledges, holes and tunnels, maybe smaller caves-or, for all we know, bigger caves. This could be nothing more than the entrance to a system of huge, interlinked caverns. We've lots of exploring still to do. We've only scratched the surface."

"Let's do it another time," I mutter, head pounding, feeling as though I'm surrounded by a layer of fire. "It's night. Time to go home."

"Not yet," Loch snaps. "I don't have to be home for a few more hours."

"Bill-E..." I groan.

"Well, Gran and Grandad will be expecting me back soon," he says. "But it's not like I've never been late before. I'll tell them I was with you, that we lost track of time-which isn't a total lie."

I want to scream at them. The fools! Can't they feel it? Even through my sickness, with a brain that's being hammered to a pulp by a searing headache, I can sense danger. The throbbing's back, stronger than ever. We need to get out now, quick, before...

Or am I imagining the danger, like I imagined the monsters in the dark? Maybe it's just my sickness that we have to fear and this is only a beautiful, eerie cave.

Even so, if I turn into a werewolf here, that's more than enough for any pair of humans to worry about. Trapped underground with a supernaturally strong wolfen beast, Bill-E and Loch wouldn't last five minutes.

"Look," I snap, "we have to go. We'll come back tomorrow and explore fully. But it's dark up top-it's night. We said we'd go when the moon rose." I stop, gather my thoughts and try a different approach. "We don't want to draw attention to ourselves. If we come home late, caked in mud and dirt, what will everyone think? If they start asking questions..."

"He's got a point," Bill-E concedes. "Gran and Grandad put Sherlock Holmes and Watson to shame. We should play it safe, act normally, especially if we're going to be coming here a lot."

"OK," Loch sighs. "But one more search before we leave." He points to the top of the waterfall, where it comes gushing out of the sheer rock wall fifteen metres above the cave floor. "Up there, those large holes. We can climb up pretty easily. I want to have a peek at them. Then we can go."

"I dunno," Bill-E says. "They're fairly high and that wall's steeper than the one we climbed down."

"What's a wall to three hardy explorers like us?" Loch laughs. "It won't take long. And if the treasure's there, we can go home on a total, triumphant high."

"Grubbs?" Bill-E asks.

I shake my head violently. I think I'm going to throw up. I'm trembling helplessly. Climbing's the last thing on my mind.

"Are you all right?" Bill-E asks, training his twin lights on me.

"Some kind of bug," I gasp. "I've had it for the last few days."

"Maybe we should get him home," Bill-E says.

"Sure," Loch grunts. "Right after we've explored above the waterfall." He slaps Bill-E hard on the back. "Come on, Spleenario-last one up's an asswipe!"

The ploy works. Bill-E forgets about me. They race to the wall and climb. Loch's laughing, teasing Bill-E, roughly urging him on. I turn my back on the pair, leaving my torch pointing in their direction, to provide some extra light for them. I stumble away and sink to my knees. Lean my head against one of the smaller stalagmites and groan softly. I feel like a corpse that's been stuck in a microwave to defrost-half frozen, half on fire. I try to control my breathing, to think calm thoughts, but my head's full of wild, animalistic images-running, chasing, ripping, fangs, blood.

I stare at my fingers-they're curling inwards. I can't straighten them, no matter how hard I try. I search within for magical warmth, the energy I've drawn upon over the last forty-eight hours, but it doesn't seem to be there for me now. Maybe the cave's got something to do with that. Or maybe I'm just out of fighting spirit. Out of resistance. Plumb out of luck.

"Not... going... to... turn," I snarl. Thinking of Loch and Bill-E, what I could do to them. Cursing myself for being so slack, not going to Dervish when I had the chance, allowing this to happen. I see now that it was fear, plain and simple. It didn't matter what state Dervish was in-I should have told him the minute he got back. I kept the news to myself because I was scared of what he'd do. I was hoping the charms of the moon would pass, that I was just ill, imagining the inner struggle. The same fear which kept me from learning the ways of magic stopped me telling my secret to Dervish. Grubbs Grady-coward of the county. And now Bill-E and Loch are set to pay the price for my cowardice.

I try yelling a warning, telling them to stay up high where I can't reach them. But my throat won't work. The vocal cords are constricting, thickening, cutting off my air supply. I guess since wolves can't talk they don't need all the throat muscles that humans do.

I pull my head back from the stalagmite, meaning to run, get to the surface if I can, before I change. Put space between myself and my friends. Lots of space.

But then I see the face again. It's in front of me. Bulging out of the stalagmite, as though carved out of rock. A girl's face. Similar to Gret's, as I noticed before, but not hers. Different. Younger. Darker hair. Smaller. Eyes and lips closed. Like a death mask.

The whispering, stronger than last night, more insistent. Certain words break through, but they're not words I know. A foreign language. Harsh and fast.

I'm staring at the face, listening to the whispers, held firm to the spot, feeling myself change, when suddenly-

A scream. Behind me. At the waterfall.

As I turn towards it, there's another scream. Then a very loud thud.

Then nothing.

I race across the cave, grabbing the torch on the way, lycanthropic fears momentarily forgotten, blocking out thoughts of the face and sounds of the whispers. There's a figure on the ground and it's not moving. That's where all my concerns focus now.

I reach the figure and gently turn it over. It's Loch. Face ashen. Eyelids flickering. Mouth opening and closing softly.

"Loch?" I murmur, holding his head up, trying to see how bad the damage is. I feel something wet and sticky smeared around the back of his head. I don't have to check to know that it's blood.

Scrabbling sounds. Bill-E hits the ground hard, feet first, having jumped from a spot two or three metres above. "Is he OK?" he shouts, panting hard.

"I don't know. What happened?"

Bill-E gulps, kneels, stares at Loch's head and my bloody hands. "He fell," Bill-E croaks. I almost can't hear him-the whispering's louder than ever, the words coming fast and furious. "We were climbing. He slipped. I... I reached for him. He wasn't far away. I grabbed. But he fell. I couldn't catch him. I tried but I couldn't..."

"Just as well you didn't," I comfort him. "He'd have dragged you down with him. Take off your coat." Bill-E gawps at me. "For under his head."

Bill-E shrugs off his jacket and balls it up. While I hold Loch's head, he lays it underneath, then I softly lower Loch down. His eyes haven't opened. He's breathing raggedly. This isn't good.

"I told him not to go up there," Bill-E says hollowly. He's crying. "I warned him. But he wouldn't listen. He thought he knew it all."

"Hush." I'm calmer than my brother. I've seen worse things than this. Blood doesn't alarm me. "One of us has to go for help. The other needs to stay here, sit with Loch, look after him."

"I'll go," Bill-E says quickly. "Please, Grubbs, I don't want to stay. Not in this cave. It's too dark. Please don't make me-"

"OK," I shush him. "You can go. Find Dervish. Tell him what happened. He'll know what to do. But run, Bill-E. Run!"

Bill-E nods, stumbles to his feet, stares at Loch's face, opens his mouth to say something, then races for the exit. I hear him scrambling upwards-but only barely, over the sound of the whispers-then turn my attention on Loch and the dark pool spreading out from beneath his head and Bill-E's blood-soaked jacket.

Talking to Loch. All sorts of nonsense-school, the treasure, holidays, girls, wrestling. I've put my coat and jumper over him. Have to keep him warm.

His breathing comes jaggedly. His eyelids have stopped twitching. His heartbeat's irregular. I keep on talking, rubbing his arms and chest, but I don't know if I'm doing much good.

The sickness is still in me. My head feels ripe to burst. Sometimes my words come out as growls, and my fingers clench while I'm rubbing Loch, digging into his cold, clammy flesh.

I fight it. Search within for warmth, energy, magic-anything. I can't change, not until Dervish comes, not until Loch's in an ambulance on his way to hospital, safe.

"Won't turn," I snarl, slapping my cheeks one after the other. "I'm not a wolf. I can control myself. Won't let the moon..."

Loch shudders. His breath stops. I thump his chest hard-then remember first aid classes at school. Opening his mouth, I press firmly down on his chest, then release him and count. One, two, three, four. Press and count again. A third time. I place my lips over Loch's. Breathe out, so that his cheeks puff up. Withdraw. Press-two, three, four. Press-two, three, four. Press-two, three, four. Mouth-to-mouth.

Trying to remember if I'm doing it right. Was it three presses on the chest, or four, or five? Should I blow air firmly down Loch's throat or-

Loch coughs and breathes again.

I sink back, whining with relief and fear. That was too close. This can't be happening. We were looking for treasure. Messing about. Loch was teasing Bill-E. Everything was normal. You can't suddenly go from that to a life-or-death situation like this.

Except I know from past experience that you most certainly can.

Besides, things weren't normal-the face, the whispers, the throbbing, the sense that we were in danger. I should have been more forceful. Made them leave. Insisted they go home.

The sickness within me grows.

The noise of the whispers increases.

Loch's blood continues to flow.

Still talking. Telling Loch he's got to stay alive for Reni's sake. "She'll be a mess for years if you die," I sob. "Trust me, I know what losing a sister does to your head. You can't leave her, Loch. She needs you.

It feels like hours since Bill-E left. Loch stopped breathing again a few minutes ago. I resuscitated him, but it took longer than the first time. I was in floods of tears by the end of it-sure I'd lost him.

What's keeping them? Damn it, they should be here by now. Don't they know how perilous this is, how much danger Loch's in? I can't keep him alive forever, not by myself. If they don't-

Loch's breath stops again. Cursing, I start with the chest pressing and mouth-to-mouth. The beast within me wants to suck in air, not breathe it out. It wants to draw the life from Loch, feed on all that blood around his head and shoulders, sip from that terrible pool, dark in the dim light of the torch. If I dropped my guard, just for a few seconds, there's no telling what it-I-would do.

The whispers increase. It's like I'm being shouted at now. I want to roar back at them but I need all my breath for Loch.

Press-two, three, four. Press-two, three, four. Mouth-to-mouth.

Nothing's happening. I don't panic. It was like this last time. I just have to keep going, stay calm, stick with it. He'll revive eventually.

Press-two, three, four. Press-two, three, four. Press...

It doesn't work. No matter how much I press and breathe, Loch doesn't respond. His face has shut down. His lungs don't move. His heart is still.

Third time unlucky.

"No," I whisper. "I don't accept this. He can't be... "No!"

I bring my hands up, meaning to press again, harder than before, wildly. But something about Loch's expression stops me. It's peaceful, calmer than it ever was in life. Staring at him, I know with total, awful certainty-he's lost. I could press and breathe from here till doomsday and it wouldn't make the slightest bit of difference.

Loch Gossel is dead.

Stumbling around the cave. The whispers deafening. Tears streaming down my cheeks. The wolf within me howling to be set free. Loch dead. Muttering, "This can't be so. This can't be so. This..."

My right foot hits either a large stone or small stalagmite. I fall flat. As I'm picking myself up, the face of the girl forms in the floor in front of me. Her expression is the same as Loch's. I gaze at her in horror. This is what Loch will be like for all eternity, or at least until his body rots. Blank, lifeless, ever still, ever serene, ever-

The girl's eyes snap open. Her lips part. She shouts at me, words I can't understand.

I scream and propel myself backwards. Scream again. Halfway through, it turns into a howl. With an effort, I force the howl down, then fix my eyes on the face in the floor. "No," I snarl, pressing my hands hard against the sides of my head. "NO!" I roar.

Something shoots out of me. A force I haven't felt in all its power since I fought Lord Loss and his familiars in Slawter. I shut my eyes, feeling energy zap out of me. The scream rises and rises. I feel as if I'm floating above the ground. I think if I opened my eyes I'd find that I am floating. I hold the scream, the cords in my throat feeling like they're going to burst, until...

A sound like cannon fire. Then sudden silence. The scream dies away. My head flops. I collapse. My hands come away from my head, to protect my face from the fall.

When I sit up, I'm breathing hard and crying. But the whispering has stopped. I glance at the spot in the floor. The girl's face has disappeared. And I don't feel sick anymore-only small, lonely and scared.

Standing, I shine the torch around, trying to pin down the source of the cannon fire. It only takes a few seconds to spot it-a large crack in one of the walls, close to the waterfall, which wasn't there before. Did I divide the rock with my magical scream, or is the crack coincidence, the result of air flowing into the cave or a change of temperature? I don't know. At this particular moment, I don't really care.

I stagger over to Loch and slump beside his lifeless form. Impossible to believe he'll never move again, or laugh, or wrestle. You think your friends are never going to die, that all the people you know and care for will be with you forever. Then the world makes a fool of you, so quickly, so simply, that you wonder whether any of your family or friends will see out another day intact.

I want to bring him back. I want to shake him, kick him, pump magic into him, make him breathe, make him live. It should be easy, like starting a stalled car or a crashed PC. There should be rules, instructions, things you can do. But there aren't. When it comes to humans, death's death, that's that, and you're a fool if you think any different.

Crying, I lean over Loch to hug his empty shell and tell him how unfair this is, how good a friend he was, how he shouldn't be dead, how much I want him to live, how scared I am. And it's only when I grab his shoulders and haul him up, pulling his head in towards my chest, that I realise-his head, the coat and the area around his shoulders... they're all dry.

At first, I'm so distraught I don't understand why that should be so strange, why it strikes me as being out of place. I'm about to dismiss it, to banish it from my thoughts, when the significance hits and I do a confused, incredulous double-take. Then, because I still can't make sense of it, I cry the question out loud, in case giving it a voice will help me find an answer.

"Where the hell has all the blood gone?"