‘She can’t be far,’ I tell him when he ends the call. Except we both feel a new urgency, after what the woman said about Casey’s manner. What if something has gone wrong with her brain?

‘You don’t know that,’ Dan says. ‘The estate is vast and she could have collapsed. Or there’s someone here who targets children on their own—’

‘Stop that. Come on. Between us, we can cover plenty of ground. Let’s be logical, divide up the territory.’

We agree that Dan will go right and I’ll go left. Bear comes with me, and when he realizes I’m not going to throw the ball for him, he keeps disappearing.

I start calling out Casey’s name and Bear joins in by yelping. I follow him into a copse, trying not to get my hopes up. When he stops, I look down to see he’s pawing the remains of a squirrel and that makes me think dark thoughts, however hard I try to fight them.

We keep walking, and the rain has soaked through my jacket and I can’t stop shivering. Bear barks again as we get deeper into the woods and runs off, and I can see he’s digging.

He heads back with the filthiest tennis ball in his mouth, pure delight in his eyes. I think I’m going to have to prise it away from him, because the more disgusting the find, the more determined he is to bring it home.

But now he drops it and tears off into the undergrowth again, running in excited circles. I follow him once more, convinced I am about to stumble into something putrid and rotting.

The tree cover means it’s less damp here and heat rises from the earth. When I breathe in tentatively, I can only smell good things, moss and leaves, like someone’s bottled the colour green. Bear keeps checking that I’m following, before bounding over more fallen branches, revelling in every obstacle. I’m not as nimble in my skirt and flat shoes, and my skin stings where I brush against nettles and brambles.

Could Casey be here? And if she is, what if she’s sick or injured? Or worse . . .

No. She was OK an hour ago when she saw the balloon woman. Well, not completely OK. Distraught and betrayed by everyone. Including me. I should have called her. Should at least have sent a WhatsApp or two, checking she was all right after finding out about her father’s lies, but I was too wrapped up in my own problems.

Up ahead, I see – or do I imagine? – the briefest flash of pale pink.

‘Casey?’ I call out.

Bear tears ahead, his dense, muscular body bred for rough terrain, for the hunt. He’s fifty metres in front of me and there’s no movement anywhere.

‘Go!’

The voice is faint. I can’t even tell if it’s a woman or a child.

But my body – and Bear’s reaction – tells me it is her.