‘I’m rubbish at Facebook, hardly ever post anything myself.’

‘I know what you mean.’

She stood back from the cake and looked at me again.

‘So, technically, I’m more of a stalker really.’

I wonder what she really thinks about those posts from Thursday night?

‘Well,’ I said, ‘Facebook’s certainly good for stalking too.’

She pointed at my chest.

‘I like your T-shirt, by the way.’

I smiled and looked down at the navy T-shirt, a speech bubble with white text inside: ‘I’m silently correcting your grammar.’

‘My wife got it for me – kind of an in-joke with English teachers. Grammar is becoming a bit of a lost art these days, with textspeak and social media and what have you.’

There was a burst of shouts and clapping and then a disappointed wail from the other room and we both turned towards the noise.

‘Better go and see what’s up,’ I said, grabbing the opportunity to get away.

I returned to the lounge, where a game of pass the parcel had ended in tears for two little girls in dresses and plaits, both of whom had a hand on the parcel when the music stopped. The rest of them, William included, stared in fascination as the two girls screwed their faces up and competed to see who could cry the loudest.

I avoided talking to Jacob’s mum again when the children trooped into the dining room for birthday lunch. As always happened at these parties they all reached first for the hula hoops and chocolate fingers, leaving the carrot sticks and cherry tomatoes untouched in the middle of the table.

Mel was in the kitchen when we got back home. Drinking coffee and dressed for tennis again. She kissed me and handed me a cup, asked me about the party, and how was swimming, and did William manage a length of the pool? A normal Saturday. Normal stuff happening. Not for the first time, I wondered if I had just dreamed the whole of Thursday evening: Ben and my wife, the hotel car park, the aftermath. All just a dream, a fiction conjured from fitful sleep.

‘A courier came,’ Mel said, indicating a small plastic-wrapped package on the kitchen worktop.

I opened it. A replacement mobile phone sent out on the insurance. God forbid we should ever have to go offline for more than twenty-four hours. I took the phone out of its box and unspooled the power cable.

‘Your phone didn’t turn up, then?’ Mel asked.

‘Nope.’

‘You sure it’s not in the house somewhere?’

‘Pretty sure.’

‘Wills has started getting a bit obsessed with phones and gadgets, remote controls, that sort of thing. He puts them in with his cars, maybe you should go and have a look.’

I plugged the new phone in to start charging it.

‘Bit late now.’

‘Have you tried ringing it?’

It occurred to me that in Thursday night’s panic, I had not even tried once to ring my mobile to see if anyone answered. And now it had been disconnected.