‘Kira!’ I pound on the door with both fists, then run round to the front of the house and stare up at the landing window. She’s vanished.

‘Kira!’ I run back to the door, twist the key in the lock and barge against the door with my shoulder. It doesn’t give an inch but the glass panel at the top rattles.

There are two small bay trees in ornate pots on either side of the door. Liz gave them to me for Christmas. I pick up the slightly smaller one and hurl it at the panel, then press my handbag against the jagged glass at the bottom and reach my arm through the hole.

I fumble at the catch as I search blindly for the button that releases the double-lock.

‘Come on, come on, come on.’

I flick it to the side, turn the key in the lock and press my shoulder into the door. It swings open and I fall inside.

‘Kira!’ I scream as I run through the kitchen. ‘Kira, no! Don’t! Don’t!’

My heart is in my mouth as I reach the bottom of the stairs.

‘I’m so sorry, Claire.’

Kira is balancing awkwardly on the wrong side of the landing banister. There’s a noose around her neck made from the belt of my white towelling dressing gown. She’s holding on to the railing but her toes hang over the ledge. One step forward and she’ll drop at least ten feet.

‘Kira,’ I say as her eyes fill with tears. ‘Don’t do this. Whatever you’ve done, whatever’s happened, we can talk about it.’

She closes her eyes.

‘Please don’t do this, Kira. Let me ring Jake and—’

She moves to takes a step into the void and I scream.

The sound makes her draw back again. The skin stretches over her knuckles as she tightens her grip on the banister. It’s not just her legs that are shaking. It’s her whole body.

‘Okay, okay. No Jake. No one else. Just you and me. Just you and me, Kira.’

She doesn’t move or open her eyes. She doesn’t speak or react in any way but I know she’s listening.

‘You can talk to me,’ I say. ‘You can talk to me about anything. I want to make things better. I want to help you.’

A low moan escapes from her throat.

‘It’s true.’ I place a foot on the bottom step of the stairs. Kira’s eyes fly open as it creaks under my weight.

‘I’ll jump,’ she says. ‘If you come upstairs I swear I’ll jump.’

‘Okay, okay.’ I hold out my hands in surrender and take a step back. ‘I’m not going to try anything. I’m not going to touch you. I promise. All right?’