A bang on the French windows startles us, and Julia’s glass slips through her fingers and shatters on the floor.

It’s Finn, his bloody palms pressed against the glass, his eyes wide.

‘Don’t let him in,’ I yell.

‘Don’t be silly, Amelia. It’s only Finn. We can’t leave him out there.’ She heads over to the French doors.

But I see the mask sticking out of his pocket. ‘Wait. No!’ I cry.

‘But he’ll freeze to death out there,’ she says, ignoring my plea – unlocking the door.

Finn stares in, not moving, his pupils dilated in bloodshot eyes, his skin red raw from the cold.

As he finally steps forward, teeth chattering, one hand on his stomach, his other loose by his side, my heart thuds, and I step backwards.

‘Julia,’ he says, his voice barely audible as he reaches out his hand towards her, in the same way the figure on the bench had – there’s no doubting he was sitting there earlier, wearing the mask.

‘Oh God, Finn.’ Julia steps forward, and I want to yell at her to be careful, that she has no idea what he’s done, but my throat swells. Words won’t form.

Julia moves outside, almost toppling on the ice, and allows him to put his arm around her shoulders. She’s helping him into the house, when I see the blood on his clothes, the drops of blood on the snow, leading to the door.

‘What happened?’ she’s saying to him, as she guides him into the lounge. ‘You’re bleeding.’

Should I run? Would I be safer out there?

‘Christ sake, Amelia,’ Julia cries, glaring at me. ‘Can I have a bit of help here?’

I stare, as she hobbles onwards, almost collapsing under Finn’s weight.

‘Amelia, please!’ she yells.

I catch up, and shudder as Finn drapes his free arm around my shoulders. We manage to get him to the sofa, where he flops down hard.

‘What happened to you?’ Julia asks him again, but his eyes have receded into his head. ‘Finn! Finn, can you hear me? Oh God, he’s been stabbed. Oh God!’ She grabs a throw from the back of the sofa, and presses it against his stomach, her hands shaking. ‘Who would do this?’

My mind drifts again to the moment before I passed out. I’d rammed the knife into him, hadn’t I? Heard him cry out in pain. But I had to do it. He would have killed me if I hadn’t. Wouldn’t he? It was him or me, and it wasn’t going to be me.

An urgent hammering on the front door brings me out of my thoughts, and I race towards it. I don’t care who it is. We’ve caught the killer. It will be help. I know it will.