‘We won’t tell Mommy.’ Was that bad, keeping secrets from the child’s mother? But I already knew she would throw a fit and I just couldn’t deal with it. I listened out for Madison splashing in the bathroom as I stripped the bed, gagging at the wet sag of the sheets, the nose-tingling reek of urine. Then I pushed open the door to see her sitting in the bath, her head bowed in shame. I picked up her pyjamas from the floor – they had little clowns on them, with gaping smiles I found slightly sinister.

‘I’ll wash these right now, don’t worry.’

Madison nodded sadly.

Abby might notice the machine running, but hopefully she would leave for yoga before going into the child’s bedroom in the morning. Would she even remember exactly what pyjamas Madison had on?

‘The water’s not too hot?’

‘No.’

I went over and laid my hand on her head – she flinched. I had never seen her naked before, I realised, and made sure to look away. ‘It’s really all right. Just a little accident, OK?’

‘OK.’ She still sounded so sad.

I took the wet sheets downstairs and bundled them into the machine in the laundry room, which was just off the kitchen, then turned it on. Would the noise wake Abby? I could make up some excuse. I was crossing back to the stairs when I saw a figure coming down. I was surprised by how much my heart lurched – was I really that afraid of Abby? Luckily, it was David, hair sticking up, rubbing his eyes.

‘Is everything all right?’ he said. ‘What time is it?’

‘Um, four.’

He cocked his head. ‘You’re doing laundry at 4 a.m.?’

This was my moment to tell the truth or lie.

‘I – I spilled something on my sheets.’ I didn’t elaborate. Maybe he’d think I got my period. ‘Sorry.’

‘Oh! Well, that’s all right.’

‘Sorry if I woke you. Madison’s up already, she’s having her bath.’ She didn’t normally wake until much later, but David wasn’t all that familiar with his children’s routines.

‘OK.’ We paused on the stairs, me going up and him going down. ‘May as well make coffee, I suppose, get a start on the day.’ Right on cue, Carson made that little choking cry that meant he was gearing up to a full screech.

‘I’d better get him,’ I said, feeling the weariness deep in my bones. Four o’clock and I was already on the treadmill.

‘All right,’ he said, turning away.

For the first time it struck me as odd, hiring a teenage girl to live in your house and go to your crying baby, while you just stand there as if you’ve never heard the sound before.

‘Casey,’ he called, as I moved up the stairs.

‘Um?’