"You're crazy."

Storming down the stairs to the main hall. Bill-E hurrying to catch up.

"It makes sense," he insists, darting ahead of me, blocking my path. "The bite marks. The way the animals were ripped up the middle. Why he collects the carcasses and incinerates them - getting rid of evidence."

"Crazy!" I snort again, and shove past him. "A while ago you told me Dervish was your father -  now you reckon he's a werewolf!"

"What's one got to do with the other?" Bill-E says. "Werewolves are normal people except around the time of a full moon."

"You're barking mad!" I shout, throwing open the front doors, stepping out into welcome sunlight. "This is the twenty-first century. The police have cameras everywhere. DNA testing. All the rest. A werewolf wouldn't last a week in today's world."

"It would if it had human cunning," Bill-E disagrees. "Hear me out, will you? I've been working this through in my head for the last few months. I've got most of it figured."

I stop reluctantly. A large part of me wants to keep on walking and not listen to another word of Bill-E's madness. But a small part is fascinated and wants to hear more.

"Go on," I grunt. "But if you start on about silver bullets or - "

"You think I want to kill him?" Bill-E snaps. "He's my father!"

Bill-E strolls as he outlines his theory. I wander along beside him.

"In movies you become a werewolf if another werewolf bites you. But I don't think dozens of people from one family would get bitten, one after another, over so many centuries. It must be passed on by genes, from parents to children. The unlucky ones are born to become werewolves. So I imagine they start to change pretty early, when they're kids or teenagers. Dervish is in his forties. If he is a werewolf, I think he's been living with this for decades.

"Werewolves can't be wild killers," he continues. "If they were, Dervish would have killed loads of people here. I've checked old newspapers in the library - nobody nearby has been killed by a savage beast any time recently."

"Maybe he roams further afield to do his killing," I insert wryly.

"I thought of that," Bill-E says earnestly. "But I've kept a close eye on him these past few months, and I haven't seen him spending nights away around full moon time. Besides, we've seen some of his local kills - the butchered animals. If he hunts and kills animals this close to home, there's no reason he shouldn't hunt and kill humans here too. But Dervish isn't a killer. If I thought there was even a slim chance that he was, I wouldn't be talking to you - I'd be telling the police."

"You'd turn in your own father?" I sneer.

"I'd have to if he was killing," Bill-E says softly. "Murderers can't be allowed to roam freely."

We're getting near to the sheds. A large sheet of corrugated iron lies on the ground between the sheds and the mansion. We head for it simply because there's nowhere better to go. This used to be a small orchard. There are several smooth tree stumps close by. Bill-E sits on one and I sit on another. I tap the corrugated iron with my foot, considering the 'evidence'.

"So you think Dervish is a werewolf with a conscience. He kills animals but not people."

"Is that so hard to believe?" Bill-E asks. "You accept demons are real - why not werewolves?"

"I accept demons because I've seen them," I answer stiffly. "And I'm sure they're demons twenty-four hours a day, corrupt and evil all the time. If you asked me to believe that people can turn into savage beasts - physically transform into wolf-like creatures - maybe I could. But I don't believe an ordinary human can change into a hairy, yellow-eyed, fanged werewolf overnight, then resume his ordinary shape the next day."

"I never said he transformed," Bill-E notes swiftly. "I think it's more a mental condition than a physical one."

"What about those creatures in the book?"

"Maybe it works different ways in different people," he suggests. "Some get it bad and change completely. Others, like Dervish, are able to control it."

"Degrees of werewolfism," I chortle. "This gets crazier every time you open your mouth."

"OK," Bill-E huffs, getting up, shoulders slumping. "Have it your own way. I thought I was doing you a favour, but if you're going to mock me, I'll just - "

"How do you reckon you were doing me a favour?" I interrupt.

"I don't live here," Bill-E says, turning to depart. "Come the next full moon, I'll be tucked up in bed, in the Vale, safe with Gran and Grandad. You'll be out here by yourself... alone in the house... with Dervish."

Hours later. Trying to laugh it off. Craziness. Utter lunacy. I shouldn't even be considering it. And yet...

In a world beset by demons, why shouldn't werewolves exist too? And I can't think why Dervish should be searching the forest for dead animals and burning them secretly. And some of the faces in the book definitely match those in the hall of portraits.

Then again, I've only Bill-E's word that the book is about werewolves. Dervish has a weird sense of humour. He might have been kidding Bill-E about the book. Maybe he even stuck in the photos and drawings himself. That makes more sense than Bill-E's werewolf theories. Much more logical.

And yet...

Dervish arrives back just before sunset. I greet him as he enters. "Go anywhere special?"

"Just for a drive," he replies, slicking down his grey hair at the sides of his head.

"Where's Meera?" I ask.

"Off touring the countryside. She's basing herself here for the next week or so, but she'll be popping in and out a lot. Where's Billy?"

"He went home."

"Oh?" Dervish pauses on his way to the bathroom. "I thought he was going to watch TV."

"He had other things to do," I lie.

Dervish continues on to the bathroom. My eyes follow him automatically, studying his face, the set of his jaw, the crown of his head, searching for abnormalities.

Night. Heavy clouds. Only brief glimpses of the three-quarters full moon.

Watching TV with Dervish - a documentary about some Indian woman that he knows. All about using people's natural body energies to cure diseases. Y-A-W-N!

A game of chess afterwards. Dervish appears distracted (or am I imagining it?). Plays loosely, less aggressive than usual. He beats me, but I take a couple of his major pieces and make him work hard for his victory.

Dervish stretches. Groans. Checks his watch. "I'm exhausted. Going to tuck in early. You staying up late tonight?"

I keep my head down. "No. I'm pretty tired too. I'll follow you up soon."

Slyly watching him trot up the stairs - not the pace of a sleepy man heading for bed.

Lining up the chess pieces on the board. Idly playing against myself. Quiet, the house creaking around me, a wind blowing lightly outside.

I abandon the game halfway through. Go up to my room. Pause at the door. This is stupid. If I leave it like this, I'll be imagining danger everywhere I look. I've got to share this house - my life -  with Dervish. I can't let something this ridiculous come between us.

Retreating, I carry on up the staircase to the top floor. Dervish's room. I stand outside a moment, getting my story straight, deciding to tell him everything Bill-E said. I grin as I picture his incredulous response. Then I rap twice with my knuckles and enter.

"Sorry to interrupt, but I've got to..."

I grind to a halt.

The room is empty.

I've explored the entire house. His study. The bathrooms and toilets. The other bedrooms. Downstairs. Even the cellar, in case he's scouring the racks, admiring his wine collection. He isn't here.

Sitting up in bed. Listening to the wind. Thinking about dead animals and old werewolf films. Afraid to sleep.

My eyes snap open. Early morning. Must have dozed off despite my fear. I roll out of bed. Grey day, sky obscured by clouds.

I pad downstairs to the kitchen. Scent of fried bacon and sausages. I push the door open slowly. Dervish inside, at the frying pan, humming. It takes him a moment to spot me. He smiles. "You're up early."

"I didn't sleep very well."

"Hungry?" Dervish asks. "Want some bacon? Eggs?"

"I'll just do toast for myself." I stick two slices of bread in. Pause over the toaster, my back to him. "I called up to see you last night," I say innocently. "Couldn't find you. Were you out?"

The shortest of pauses. Then, "Yeah. I went to a pub in the Vale. Met Meera there. She went on somewhere else afterwards. Sorry I didn't tell you."

"That's OK." I reach for the butter. "Did you take the bike?" If he says he did, I'll know he's lying - I would have heard it.

"No," he says. "I walked. I don't hold with drinking and driving."

I turn from the toaster, smiling. Dervish is concentrating on his bacon. I can't believe I spent so much time worrying last night. I open my mouth to tell him about yesterday's scene with Bill-E.

Then close it.

Dervish is reaching for an egg with his right hand. My eyes are attracted to his nails. Not long -  but jagged. Dirty. Red stains under the tips.

It could be paint or rust or something he ate in the pub the night before.

Or it could be blood.

Staring. Staring. Staring.

The toaster pops behind me.

I almost scream.

Dragging clothes out of the washing machine. If Dervish walks in on me, I'll say I left money in one of my pockets.

Underpants. Socks. Shirts. Trousers. Finally - a blue denim shirt with a small eagle insignia on the left breast pocket. The shirt Dervish was wearing last night.

I run my nose over it. Unpleasant and sweaty, but not smoky. Not beery. Not like it would smell if he'd spent a few hours in a pub.

Sitting by the phone. I want to call Bill-E, tell him about Dervish disappearing, the blood, the scentless shirt. Except -

He might have gone to the pub like he said.

Maybe he changed shirts before he went out, after I last saw him.

The stains under his nails could have been anything.

If Bill-E hadn't filled my head with rubbish, I'd have thought nothing of Dervish slipping out without telling me. It's not the first time he's done it. He gives me plenty of space and freedom, and expects the same in return. Nothing suspicious about that.

But what does he do when he's out by himself? Where does he go? Did he really meet Meera in the Vale?

If so, why didn't she come back here with him? And if he changed shirts before he went out, why isn't the one he wore to the pub in the machine with the rest of his dirty laundry?

Carcery Vale. Outside the Lion & Lamb. There are several pubs in the Vale. I want to go in to them all to check if Dervish was in town last night.

My story - Dervish lost his watch, and sent me to ask if it had been found. He can't remember which pub he'd been in, so I'm doing the rounds of them all.

Holding me back - somebody might mention my queries to Dervish.

In the end I turn away from the Lion & Lamb and make for home. Not reckless or scared enough to check on Dervish's alibi. Not yet.

Night. Alone in the house. Meera called in this afternoon. I wanted to ask if she'd enjoyed the pub last night, but Dervish was there and I didn't want to be so obvious. They left a few hours ago. Dervish told me they were going into the Vale and not to wait up for them. Asked if I'd like them to bring back anything. I said some crisps would be nice.

A truly crazy thought - what if Dervish and Meera are both werewolves? I cast that from my thoughts even before it's fully formed.

In one of the spare bedrooms, close to the lower end of the house, where the brick extension is. A clear view of the road from here. The room across the hall has an equally good view of the rear yard and sheds. I've left the window open, so if there are any noises, I should hear them.

Glued to the front window. Hoping to see Dervish and Meera staggering back from the village, singing drunkenly. Planning cutting comments for Bill-E. Wondering if this is all a big gag designed to scare me. I'll be mad as hell if it is - but relieved at the same time.

After midnight. Eyelids drooping. A clanging noise out back jolts me out of my half-daze.

I bolt through to the back room. Edge up to the open window. Peer out. The clouds aren't as thick as they were earlier. An almost full moon lights most of the yard, though drifting clouds create random stretched shadows.

Dervish and Meera are by the sheet of corrugated iron where the tree stumps are. They're sliding it over to one side. Behind them, on the ground, half-hidden by shadows, something large wriggles. I train my sights on it. Moments later, the clouds drift on and moonlight falls directly on the creature.

A deer, its four hooves bound together with rope, its snout muzzled.

Dervish and Meera finish with the sheet of corrugated iron. I spot two large wooden doors set in concrete in the middle of the ring of tree stumps. A thick chain and lock. Dervish bends to it, takes a key from his pocket, fiddles with the lock, throws the chain to one side and hauls the doors open.

Steps leading down beneath the ground. Dervish picks up the deer and drapes it over his shoulders. It struggles. He ignores it and starts down the steps. Meera follows, pausing to swing the doors shut behind her.

Clouds scud across the face of the moon. I stare at the doors in the ground. Silent. White-faced. Petrified.

Waiting for Dervish and Meera to come out. Chewing my fingernails. Going back to my earlier crazy thought - what if they're both werewolves? I try to cheer myself up by remembering his oath when I moved in - "You'll be safe here." Wondering if that still holds true.

Minutes pass. Ten. Fifteen. Half an hour.

Thinking - they didn't look different when they took the deer down. No extra hair. No sharp canines. Wearing their normal clothes. They weren't howling at the moon. Dervish was able to insert the key into the lock, so his hands couldn't be twisted into animal-like claws. Not the appearance or actions of werewolves.

Forty-five minutes. Fifty. Coming up to an hour when... they reappear.

But not through the doors in the ground - instead, from the kitchen!

They walk out of the house, over to the wooden doors. Dervish takes the length of chain, runs it through the two large handles, then locks it. Both of them carefully slide the sheet of corrugated iron back over the doors, hiding them. They drag their feet over the marks in the dirt left by the corrugated iron, masking the tracks. Wipe their hands clean. Dervish spares the surrounding area one final glance, then they return to the house.

As soon as they enter, I close the window and race for my room - I don't want them to find me here.

Under the covers, fully dressed, shaking.

Footsteps on the stairs.

I shut my eyes and feign sleep, expecting Dervish to look in on me. But the footsteps continue up to the top floor - his study.

I wait several minutes. When there are no further sounds, I slip out of bed, undress and put on my pyjamas, then sneak back to the rear bedroom. (I can pretend I'm sleep-walking if they discover me now.)

Studying the sheet of corrugated iron. Picking at the puzzle. Dervish and Meera went down the steps in the rear yard, but came up through the house. There must be a secret passage to somewhere inside the mansion.

Quick calculating. Flash upon the obvious answer - the cellar. The wine just a ruse. Dervish doesn't want to keep me away from the cellar to protect his prize vintages, but to safeguard whatever lies beneath.

Bed. Impossible to sleep. Knees drawn up to my chest. Trembling. Clutching a silver axe which I took from one of the walls. Praying I don't have to use it.

Shortly after dawn. Eyes drooping. Fingers loose on the axe handle.

The door bursts open. Meera barges in. I try to scream but my throat constricts and all I manage is a thin squeak.

Meera's holding a bag. She jabs a hand into it. My imagination fills the bag with all sorts of horrors. I struggle to bring the axe up but it catches on the sheets. Meera pulls a cluster of objects out of the bag and lobs them at me. I cringe away from her, wishing I could sink through the wall behind me.

Some of the objects strike me dead in the face. I gasp, desperately swat them away, then blink with surprise as I realise what she's throwing -

Crisps!