Get up, screamed my brain, but my legs struggled to obey. At the other end of the bedroom, Rosie was also down on the floor. She was hidden by the bed, but the cracking of bone and the tearing of flesh and the sound of her frenzied screams told me a very different Rosie was about to get back up.

A chill draught rolled in through the window. Shakily, I placed my hands on the sill and pulled myself to my feet. A small porch with a slanted slate roof sat just outside.

As Rosie continued to writhe on the floor, I clambered through the open window and let myself fall on to the porch roof. The slates were slippery and I lost my footing right away. My b.u.m thumped against the roof, and then I was falling. The snow proved to be an effective cushion again, and I escaped unhurt from the drop.

My legs were still unsteady as I began to run in the direction of the police station. My hands fumbled for the walkie-talkie as I ran. *Ameena. Billy. You there?'

Nothing. Then a crackle. Then, *Finally,' Ameena said. *Where are you?'

*Heading your way!'

Static hissed at me for a moment, before Ameena's voice broke in again. *You can't come here. Turn back. You hear me?'

I heard Billy's scream in stereo a" over the radio and from just around the corner. Ameena swore, then there was a clatter, and then there was nothing but the soft crackle of static.

*Ameena?' I said, jabbing the speak b.u.t.ton. *Ameena? Answer me.'

KA-RAAASH!.

The bedroom window and part of the wall behind me erupted. A snarling, screeching monstrosity landed on all fours in the garden, making the ground tremble beneath my feet.

I hurled myself on, tripping and tumbling through the snowdrifts. I had to get to the police station. Had to get away from the monster that had been Rosie. Had to make sure Ameena was...

Was...

The police station was half-buried beneath an onslaught of screechers. They were there in their hundreds, battering against the walls, throwing themselves through what remained of the gla.s.s doors.

There were even some on the roof. I could see Billy and Ameena swinging at them, knocking them back, but there were more climbing up on all sides, and others still behind them.

Some of the screechers were bent double, howling and screaming, the bones erupting through their flesh as they changed a" evolved a" into Beasts.

I stopped. There was no point running now. There was nowhere left to run to. Instead I turned around, and got my first proper look at the thing that Rosie had become.

It looked like the Beast, only a new and improved model. Its head and body were bigger, its limbs longer, the muscles more defined. An exoskeleton of ragged grey bone almost covered it completely. Other bones jutted from its joints like machete blades, each one more lethal-looking than the last.

The mouth was made up of four sections. They all opened outwards as the creature launched itself at me, revealing four complete rows of saw-like teeth. A shock of electricity zapped through me. It took every ounce of my willpower to push it away. My dad needed me to use my powers so he could unleash the Darkest Corners on the world. This, all this, was just a taster of what would happen if I did. So I wouldn't. I wouldn't help him. I wouldn't give in.

Even if it meant dying.

I held up my hands, ducked down, screwed shut my eyes. The monster roared as it descended on me, closing in for the kill. In the darkness behind my eyelids, I heard another sound a" another roar, just as wild and as savage as the first.

Opening my eyes, I saw not one but two monsters, joined together, each one tearing and clawing at the other. They crunched on to the snow in front of me, then bounced over my head. They were still spitting and swiping at one another as they rolled and spun down the hill towards the police station.

The sound of the Beasts scattered the screechers. They fell and leapt and clambered over one another in their hurry to escape the approaching monsters. Not that the monsters had noticed them. They were too busy fighting, too locked in battle to notice anything else going on around them.

Up on the rooftop, Ameena kicked the last of the screechers off, then s.n.a.t.c.hed up her walkie-talkie. *What the h.e.l.l's going on?' her voice hissed at me. *Why's there two of them?'

*One of them's Rosie,' I explained. *The bigger one.'

*I knew there was something dodgy about that girl! No one cries that much.' Ameena almost sounded pleased. *Not so pretty now, is she?'

*The mucus is a bit off-putting, yeah,' I said.

*How come they're fighting?'

I hesitated, my finger held over the talk b.u.t.ton. Eventually, I pressed it. *The Beast... saved me.'

A static buzz, then: *Why?'

I considered just coming out with it, but decided I should build up to it gently first. *I thought the Beast was the one biting people and turning them into screechers, but it isn't. It's Rosie. She's the monster. She bit someone and turned them into that thing. The Beast, it was just Rosie's first victim.'

I hesitated again. I didn't want to believe what I was about to say, but what choice did I have? It was the only answer that made sense. *Or rather, she was the first victim.'

The monsters rolled apart and turned to face one another. The Beast a" the first one a" stood with its back to me, blocking me from "Rosie's" view. It was crouching low, its limbs tensed, ready to leap into battle.

*I thought whatever had attacked the policewoman had taken Nan prisoner, but... these things don't take prisoners. You either outrun them or you die, and Joseph told me Nan wasn't dead.'

The walkie-talkie gave a crackle. *You're not saying what I think you're saying?'

I looked across to the monster that had just saved my life. *I... I think I am,' I said, nodding slowly. *The Beast didn't take my nan. The Beast is my nan.'

he Rosie-monster let out a bellowing cry, drowning out most of Ameena's response.

*...what you saying? Your nan's brain's in that thing?' was all I caught.

I watched the Beast snap and snarl, trying to scare its opponent into running away. *I don't think so,' I replied. *The screechers, they've all lost their minds, and I think so has Nan. Mostly. But there must be a part of it in there that recognises me, or something. She's a monster, but a monster who doesn't want to see me get hurt.'

*That's convenient.' I could suddenly hear Ameena's voice in both ears. I turned to find her hurrying up behind me, with Billy at her heels.

The creatures screeched and howled as they resumed their fight. Rosie was bigger and more powerful, but the Beast was fast. It slashed out with a bony spike just as Rosie charged towards it. The blade pierced Rosie's shoulder and was driven deep in by the monster's weight.

*Way to go, Kyle's nan,' Ameena whistled, but she had spoken too soon.

There was a loud krik of breaking bone and the Beast let out an agonised howl. Rosie pressed forward, appearing not to notice the spike sticking out of her shoulder. Her fist slammed like a sledgehammer against the Beast's chin, flipping it on to its back. It shrieked again as its weight snapped the spikes that jutted out from its spine.

Rosie was on it in a heartbeat, thundering more blows against its head, slashing it with her bony blades. Thick, oily blood began to stain the snow around them, and Rosie threw back her head and howled in triumph.

*She's killing her,' I realised. *She's going to kill her!'

I moved to run forwards, to help, but Billy caught me and held me back. *You can't!' he told me. *You can't get in the middle of that, you'll be killed.'

*Get off, Billy,' I growled. *I'm not just leaving her.'

*Of course not,' Billy said. He gave me a curt nod and let go of my arm. *But just... let's be careful. I've got your back.'

He extended a hand to me. I shook it without hesitation. *Thanks, Billy,' I said.

*Can we save the bromance, please?' Ameena said. *Kyle's nan. Fighting a monster. Remember?' She shook her head. *G.o.d, my life just gets weirder and weirder.'

*Um... OK, here's the plan,' I said. *Ameena, stick next to me.'

*What about me?' Billy asked.

*s...o...b..a.l.l.s,' I said.

Billy raised his eyebrows. *s...o...b..a.l.l.s?'

*Hit the big one with it. Pelt it as hard as you can.'

*Why?'

*To get its attention. To annoy it.' I patted him on the shoulder. *I know you can do annoying, Billy.'

*Maybe I should do the s...o...b..a.l.l.s?' Ameena suggested. *I'm a better aim. Billy and I should swap.'

*No!' I said quickly. *Definitely not! Billy, s...o...b..a.l.l.s, Ameena with me.'

Billy hesitated. *But... but what if it comes after me?'

*That's the entire point,' I told him, then darted off before he could complain.

Rosie was still pounding on the Beast. She raised both arms above her head then brought them down hard. The Beast squealed as Rosie's exoskeleton smashed hard against its face.

*Now, Billy!' I hissed. I'd pulled Ameena off to one side, out of Rosie's direct line of sight. Billy wasn't so lucky. He was standing directly in front of her. All she had to do was raise her head and she'd be looking straight at him.

Billy, to his credit, did as he was told. Crouching, he hurriedly pressed together half a dozen s...o...b..a.l.l.s and cradled them in the crook of his left arm. With his right he picked up the first one, took aim, and threw.

The s...o...b..ll landed silently in the snow beside the writhing bodies of the battling Beasts.

PAF ! The second one found a target, but it was the wrong one. Pinned below Rosie, the Beast gave a growl as the s...o...b..ll splattered across its head.

*He's useless,' Ameena muttered. *I'm swapping places.'

*No, you can't,' I told her, holding her back. *I need you here with me.'

*Why? What for?'

I felt my lips go dry. *Um... you'll find out.'

The third s...o...b..ll exploded against the Rosie-monster's chest. Billy recoiled in horror, getting ready to run. But she kept pummelling on the Beast, clawing at it, biting at it, and Billy took aim once again.

PAF ! The s...o...b..ll struck her right in the centre of her face. Her head snapped up and her black eyes became slits as she locked on to Billy.

*Um... hi,' he whimpered, and then he dropped the remaining s...o...b..a.l.l.s, turned on his heels, and ran.

With a kick of her back legs, Rosie set off in pursuit. Billy screamed as he ran. He dodged between cars, only for them to be flattened beneath Rosie's immense weight.

*She's going to kill him,' Ameena winced. *She's too fast.'

I hurried over to the Beast. It a" she a" lay on her back in the blood-slicked snow, barely moving. Barely alive.

*Hold on, Nan,' I said softly. I rummaged in the snow beside her until I'd found what I was looking for. *You're going to be OK.'

I ran back over to Ameena, struggling with the weight of the object in my hands. *What are you doing with that?' she asked.

*No time to explain,' I said. I felt my cheeks p.r.i.c.kle red. *And, um, whatever happens next, don't hit me, OK?'

Her eyes narrowed. *No promises.'

*Right,' I nodded. My hands were shaking and my head felt light at the thought of what I was about to do. *Here goes.' I put a hand to the side of my mouth, took a deep breath, and shouted as loudly as I could. *Hey, Rosie!'

Across the street, Rosie had just begun tearing through a fence Billy was using to hide behind. At the sound of my voice, she stopped. *Over here!' I cried, waving one hand above my head. With the other, I wedged the thing I was holding into the snow between our feet.

Rosie's face drew back into a snarl. She began to advance slowly. That was no use. I needed her running, charging at me, full speed. I'd hoped I might not need to put the second part of my plan into action, but it looked like Rosie was leaving me with no choice.

*I just wanted to let you know...' I began. With my free hand I grabbed Ameena by the front of her coat, pulled her in close to me, and kissed her. Her lips were cold and chapped and her eyes were wide with surprise. As first kisses went, it probably wasn't an all-time cla.s.sic, but considering the circ.u.mstances, I could be pretty sure I'd remember it for the rest of my life.

I leaned back, flashed Ameena an apologetic smile, then turned to the Rosie-monster, *...you're dumped.'

That did it. She set off like a racehorse from the stalls, splitting the night with her terrible screech. The ground shook beneath us. The snow bounced into the air, as her colossal feet pounded against the pavement.

With a final, blood-curdling scream she launched herself towards us, arms splayed wide. Shoving hard, I sent Ameena stumbling backwards. At the same time, I threw myself clear, leaving only the long broken spike of the Beast's bone sticking up from the ground.

Rosie's black eyes widened as the spear-like point pierced the centre of her chest. There was a crack, then a scream, then the sound of something wet being torn in two. The bone burst through Rosie's back and she hit the ground, face-first.

For a moment, she flailed around, coughing and gargling as her life ebbed out on to the snow. And then, like that, she stopped.

*I don't believe it,' Ameena said, her voice a hushed whisper.

*We did it,' I nodded.

*What? Oh yeah, that,' she nodded. *But I meant... You kissed me!'

I turned to look at her, trying to read her face. *Yes. I did. Sorry.'

She nodded. *So you should be,' she said. She punched me on the arm, but I couldn't help but notice she didn't hit me nearly as hard as she usually did.

*We did it,' I said again. *And I didn't even have to use my powers.'

*Still the little problem of the infected villagers,' Ameena reminded me.

I sighed. *Don't spoil it.'

Billy ran up to join us. He was breathing heavily and his face was as white as the snow. *Did I do good?' he asked hopefully.

*You were great, Billy,' I said, but my attention was now on the creature that had once been my nan. Her breathing was shallow, her body awash with blood from her many gaping wounds.

Before I could approach her, though, I heard a slow hand-clapping from somewhere behind us. I turned and an all-too-familiar face smirked back at me.