‘But isn’t it better for Dad to think that Mark’s OK than to think he’s horrible and we hate him? He’ll only worry about us.’

‘He’s not going to worry. He never does. I mean, he might, for five minutes, and then he’ll just go and have another drink. If you big up Mark, all you’re going to do is make tonight more awkward than it needs to be. Just play it down, OK? Chances are we won’t see Dad again till Christmas and by then Mark might have disappeared back where he came from, who knows?’

She looked at me, all wide-eyed and innocent. ‘But he isn’t going to disappear.’

‘How do you know?’

And that was it, like a switch being flipped. Suddenly she was looking at me as if she was about a million years old and had seen everything. Her eyes had gone very dark, almost all pupil, and her face was as still as a mask. There was a kind of power coming off her like when something radiates heat and it distorts the air. Like invisible lightning. She was scorching. I don’t know how else to describe it. She was my sweet little sister and about the least scary person in the world, but at that moment she was terrifying.

I’d never seen Ellie change like that. I’d never seen anyone change like that.

Then she looked down at the tablecloth and put her hand up to her forehead, and when she faced me again whatever it was had passed.

‘I just know,’ she said.

Dad came back, weaving, but only slightly. He sat down and said, ‘So I suppose Mark’s taken you all out, has he? Given you some special times to remember him by?’

He was smiling as if to imply that it was all fine with him, he didn’t care that much either way. Except it was obvious that he did care. Not enough to turn up on time to see us, but enough to mind when Mum seemed to be auditioning his replacement.

‘Please, let’s not talk about Mark any more,’ Ellie said.

She had gone so pale it was as if there was no blood left in her at all. She stood up and pushed her chair back and hurried out of the restaurant, as if an alarm had gone off and she was only reacting as any sensible person would do – except no one else, me included, had heard it.

Ellie felt faint, as it turned out. She wasn’t well. She wanted to go home. Dad sighed and grumbled and rang Mum, and said he’d bring us back.

‘We could still spend some time together,’ I said diffidently, but he pretended he hadn’t heard me.

It took a while for us to get a taxi, but once we were on the way, we seemed to get home in minutes. When we got to our street Dad paid off the taxi driver and said, ‘I’ll come in with you.’