And she turned away and hurried out to the landing, and began to scamper down the stairs.

‘Yeah, well your dad isn’t all that either,’ I muttered, and started after her.

We found Mum and Mark in the kitchen, playing kiss-and-make-up – they jumped a foot apart the minute we came in.

Mum ran a hand through her hair. She was flushed but happy and I could see that whatever he’d said to her, she’d decided that he was the wronged party and she was going to feel sorry for him and forgive him. Well, what did I care? It was really nothing to do with me. Or not much, anyway.

Ellie glowered at both of them and I suddenly got a glimpse of the kind of teenager she might become. Happy days ahead – though I’d be well out of it by then. I just had to get through the next few years… I figured that once we’d moved, I could probably come up with a couple of reasons to get the train back to London, and talk Mum into letting me go on my own. After all, she was going to be pretty distracted once the baby came. That way Jake and I would be able to carry on seeing each other.

I fiddled round on my phone while Ellie sulkily read her book and Mum and Mark looked round the garden. Then Mum kissed Mark goodbye and they both told each other they wished we could stay, and she drove us back to London.

Mum asked us what we thought of the house and we both said we liked it, and that was that. After a while Ellie fell asleep in the back and I told Mum I didn’t think the thing about the kid was that big a deal and I was sure Ellie would come round to the same way of thinking once the shock of it had worn off, and Mum seemed reassured and I decided it was all going to be fine.

But that night Ellie woke me up – not the way she sometimes did, by crying out at a nightmare. Instead I surfaced to hear her quietly sobbing.

I switched the bedside lamp on and scooted across to her bed, and she sat up and I held her tight. She was cool and clammy to the touch and shivering slightly, as if she’d caught a chill.

‘It was only a dream,’ I said, but she shook her head.

Her body felt as light and insubstantial as a bird’s, as if she was hollow. I could make out the bumps of her backbone through her nightie; she didn’t have any spare flesh on her. She was all nervous energy, like a weathervane spinning round in a storm.

She said, ‘Didn’t you feel it? When we were in the car coming home. It was like a dark shadow.’

I tried to remember what the drive had been like. Some spooky woods. The countryside, which was fairly creepy in itself. So much easier to hide secrets in a big landscape with hardly anybody around. Then we’d got onto the motorway and joined the familiar London traffic, and finally we’d got back into the flat and I’d barred Ellie from our room so I could message Jake.