Anna taps on the flimsy door. ‘You coming out?’ She pauses as a woman bangs into the cubicle next to mine and retches. ‘It’s not exactly five-star luxury in here.’ Her voice is fuzzy at the edges.

‘Dunno. I might do when they’ve all left.’

She laughs. ‘Come on. Let’s get our coats and sneak off. They won’t be bothered.’

I open the door and go to the sink, turning to smile, grateful that she understands. ‘I’m not dragging you away when you’re having a good time.’

‘I’ve had enough.’ She pulls her fingers through her hair and yawns. ‘You all know each other so well and the drunker you get, the cosier you become. I’m better off leaving before it becomes obvious I’m the lemon.’

‘Anna! You are no such thing. I don’t feel part of it tonight either. I’ll stay if you want me to.’ I’m prepared to hang around for another half-hour if my presence gives her confidence.

‘No. Really, I’m done.’

‘OK. But we’re not sneaking off. We’ll say goodbye properly.’

In the event, I acknowledge that Anna is right. They don’t mind her being there, are pleased she came, but are equally happy that she’s leaving them to it now. As for me, Mara reaches out and takes my hand, and the others jump up and surround me, insist I call if I feel down and if there is anything they can do to help, I mustn’t hesitate, and they will have Lottie whenever. No problem. Only say the word.

‘Call me,’ Cassie says, and I can see that she’s hurt that I’ve chosen Anna to lean on. But the truth is, I’ve recognized in Anna someone as torn to pieces and patched-up as myself.

I open my eyes. I must have dozed off. ‘Where are we?’

‘About to cross the river,’ Anna says.

I lean forward as we sweep on to Waterloo Bridge, so that I can enjoy the light show. The drink must have made me maudlin because the Millennium Wheel moves me to tears, and so does the white dome of St Paul’s and the skyscrapers with their aircraft-warning lights, like a cherry on top, and the cranes rising like aliens from the streets.

‘So, tell me about Lottie’s father,’ Anna says. ‘What happened with him?’

‘I was too young. It didn’t work out.’

‘But you must have loved him, to have his child?’

I pause. ‘I think it was more infatuation.’

‘On his side or yours?’