"Do you think she'll change?"

Alex is looking just as anxious and edgy as the first time she asked me this question. She's been asking me the same question since the birth, in fact, and Serafine is now almost three weeks old. I take a moment to glance at the clock beside the notice board before I answer her; it's 3:50pm on a weak, blustery January afternoon, and moonrise is due in just under three quarters of an hour.

"I don't know, Alex," I say, irritably, in spite of my desire to remain on an even keel, a futile hope at best when I'm on final approach to the change myself. "How the hell should I know? There's no instruction manual for this, is there?"

I've gone through nine changes myself, and I'm still getting used to the symptoms. They're pretty vague and hard to describe, but it starts with an over-abundance of nervous energy, meaning that I simply can't settle. I itch all over, slightly but persistently, like a case of the hives. My long bones ache, particularly in my legs. And I get mad...boy, do I get mad. It's taking everything I possess not to snap any more than I just did, and Alex can see this, but she's still looking unhappy and now the baby's crying, a newborn's almost breathless squeal that sounds more like a kitten than a human infant. Alex moves to pick her out of her crib and shush her gently.

"I'm sorry for being concerned about our daughter, David," says Alex, her voice low and smooth; deceptively so, in fact, as there's still a clear undertow of bitterness there. "And I'm sorry for not wanting to have to deal with having two werewolves in my home when one is bad enough," she adds, her tone dropping to a sweet murmur as she presses her lips to the top of Serafine's fine-haired skull.

I'm thinking it's high time I retired to the cellar. In what's quickly become a carefully crafted routine, I've set a bucket of bloody steak and beef bones down there beside an old mattress; this latter item is already torn to shreds and will need replacing before next month. It also stinks, quite frankly. The painful truth is that it's hard to housebreak a werewolf, and the cellar reeks of eye-watering musk in spite of regular applications of bleach.

Serafine's stopped crying, so Alex sets her back down gently before laying a hand on my arm. I twitch violently. Reflex wants me to turn and attack. I bite down on it as hard as I can, which isn't exactly a metaphor as I feel my teeth sink into my tongue as well. There's blood in my throat now but instead of goading me, it brings me back down a lower plateau and I am, at once, a touch calmer. I turn around, shamefaced.

"No, I'm sorry," I say, moving closer to her. "It's just -"

"I know. You don't have to keep explaining."

"I feel like I do, though."

"There's only so much of this I can understand," Alex adds, and looks up at me from the loose circle of my arms. My eyes are watering a little and I'm perfectly aware that they've already begun to change, lightening from brown to amber. She's seen this before, though, and to give her due credit she doesn't react to it any more. "But I'm trying. I didn't sign up for any of this, but I love you. I love Serafine. And I'm trying to come to terms with it all in one go as well as looking after a new baby. Please understand that all of that's going to take some time."

I do understand, and I always have, but now is clearly not the moment to go into it. I can feel the lining of my throat roughening, and I know I'm out of time, at least for today. I release my grasp on Alex's waist and back away from her, craning my neck to stare out of the window. It faces due west, so all I can see is the diffuse globe of the watery sun as it chases the horizon behind a veil of insipid cloud. Somewhere to the east, unseen, the moon's about to take to the sky.

"I've got to go," I say, and I'm trying to speak softly, but there's already a distinct edge to my voice and it's dropped half a register. She nods, then stares at the baby for a second. Serafine's gone back to sleep, but I can see that it's a troubled slumber. Although she's quiet now, her little hands are curling and uncurling as she stirs and her rose-pink lips are puckering now and again.

"Let me help," Alex says, and I'm stopped in my tracks for a second, wondering what she means. Before I can ask, though, she's turned away and is adjusting the blanket in the crib, covering the baby a little better. The blanket's patterned with lambs, and in spite of the situation – or hell, I don't know, maybe because of it – I feel an outrageous, almost explosive urge to laugh. This passes as quickly as it arrived, however, and before I can say anything else Alex has taken my hand and is leading me down to the cellar.

As I mentioned before, it stinks down there, and before now I've attended to my incarceration alone, not wanting to subject Alex to that grim task. I'm feeling slightly dizzy and disoriented now, though, and I'm in no shape to refuse her even though I can see her wrinkling her nose at the smell.

I strip off my clothes as she closes the door behind us. It's yet another absurdity, but I know from experience that if I don't take them off they'll only be ripped to shreds anyway. I hand them to Alex, and she folds them up and places them on a wooden chair in the far corner, out of the circle of reach afforded me by the limits of the chain.

Oh yes, the chain. It would be far too risky to rely upon a locked door alone, even if that door were up to the job of restraining a furious beast the size of a grizzly bear, which it isn't. The chain is heavy gauge steel, welded to a shackle at one end and padlocked around a thick iron water pipe at the other. I lower myself to the mattress and reach for the shackle, but Alex is already there, retrieving the key from the lock and closing it around my right ankle before locking it once more. The cellar's cold and the metal's colder, but I'm used to it, and I know it's got to be done unless I want to end up with half a dozen more deaths on my conscience.

"Is that all right?" asks Alex, her voice shaking with concern. She clearly wants to get back upstairs to keep watch over our daughter, but she's torn between that and staying to see me change, too. It's simple curiosity. She's always claimed she doesn't want to see what I become, but part of her does. In her situation, I would too.

"It's fine," I say. I want to say more but my ability to enunciate is fast deserting me. I find my gaze fixing on the soft white skin of her throat, but not with my usual, human intent. "Get out of here," I bark at her, and it is a bark, with a jagged edge and foul phlegm curdling in the back of it. My ears are pricking as my hearing sharpens; Serafine's started to cry once more, but that thin, plaintive whistle is starting to coarsen, and with my last lucid thought I realise that I was right all along. Our child has taken after her father.

My whole body is tied in sudden, furious knots, and I'm thrashing and shrieking in my cold steel restraint. Everything I can see is the colour of fresh blood, and through pain-drenched eyes I watch Alex back away from me, stumble up the stairs in a flood of weeping and disappear. The cellar door slams, and I hear the key turn in the lock. Then, as my bones begin to warp and my skin prickles with fresh, wiry hair, I hear three things. The first is my own growl, which starts low in my chest but bursts free as a piercing song of suffering. The second is Alex's cry of anguish from the nursery upstairs.

The last is a small, sweet, almost melodious howl that mingles with my own.