‘No, I can’t.’ Fury is bubbling up in me now. I’m gripping his phone so hard it’s a wonder I don’t crush the screen. I bang harder on the door, at which Andy curses under his breath – but still audibly – then there’s more sloshing and ostentatious sighing as he hauls himself out of the water. He opens the bathroom door wearing his dressing gown unbelted and stands there dripping all over our wooden floor.

‘What’s up?’

I thrust his phone at him.

‘What is it?’ He gives me an uncomprehending look.

‘I read your texts. I read them just now. The ones from Estelle.’

My back teeth are jammed together and my heart seems to be battering inside my chest. Andy hesitates before taking his phone from me. And I know, as a sense of grim resignation settles over his face, that there’s no innocent explanation for these messages.

The astronomy app didn’t malfunction. No one hacked into his phone. My husband has been seeing this woman, and calling her ‘Baby’, and our marriage will never be the same again.

Chapter Five

The terrible early hours of Sunday, February 17

The way he tells it, it was a dreadful mistake. Too much drink after a heady day at that conference in Manchester, back in October: ‘So full on, Viv. You know what these things are like, especially on the last night when everything’s wrapping up.’

October! A whole four months ago! That’s sixteen weeks … a hundred and, um, a lot of days. And, actually, I don’t know what ‘these things’ are like. At Flaxico we don’t go away for conferences. We don’t even have any. Instead, we have ‘ideas days’, held in what’s known as the lower basement (as opposed to the upper basement), down in the bowels of the earth, perilously close to its fiery core, which is never used at any other time.

There’s no shagging at these, obviously. There isn’t even any booze; just a dismal buffet sent down to our windowless bunker from the canteen, comprising cress-garnished sandwiches containing something called ‘cheese savoury’ (i.e. grated cheese and onion bound with generous quantities of mayonnaise) plus small, sticky, factory-made cakes sweating in their cellophane wrappers. But that’s not the issue. The real point is, even if I did know what ‘these things are like’, I can’t imagine any situation where I’d have slept with someone else. The naughtiest thing I’ve ever done in a hotel was pinch an extra shampoo from a chambermaid’s trolley.