‘Yes, you do that.’ She waves as she walks away, her legs like lead weights. Something makes her turn and glance up at their bedroom window, where the silhouette of someone quickly disappears, and the countdown begins.

Greg doesn’t come home in the evening. He is angry with her, deliberately staying late at the hospital. All day she’s refrained from messaging him, but now it’s important that she does.

No alarm bells ring. Greg is avoiding further conflict, staying away until he’s certain Sienna won’t push him any more. He should realise that this will only make things worse. There’s another alternative, of course, one that she would never have considered him capable of before: he’s punishing her, deliberately avoiding her because she pushed him too far: to a place he didn’t want to go. He’s already acted out of character, and given the magnitude of their argument, it makes complete sense that he is making her suffer, even though he’s never been that type of person before. It wouldn’t be the only unprecedented thing to happen in the last week.

Sienna doesn’t panic. Even when she climbs into bed just before ten p.m., staring at the empty space beside her.

It’s only when she wakes the next morning – Greg’s side of the bed cold and uncreased – that she knows something is wrong. He might have avoided her for a while, but he would never have been so cruel as to stay away the whole night.

The house is silent, emptiness filling the walls, but she checks every room; it’s possible he’s decided to sleep in the spare room, or downstairs. There’s no sign of him. His mobile is still off when she tries calling again, and now anxiety seeps through her veins, spreading throughout her body, crippling her.

She should call Abby. She doesn’t know why, when Abby hasn’t even called her back, but she needs her friend. She is the only person Sienna can talk to, the only one who will understand her fear, even if something has shifted between them.

‘Greg didn’t come home last night,’ she says after the beep. She knew before she tapped Abby’s name that she’d have to leave a message, that Abby wouldn’t answer. She takes a deep breath. ‘I’m really worried. Can you call me when you get this?’

It takes a minute and a half for Abby to call back, ninety long seconds in which Sienna’s panic expands and grips her in a chokehold. Hearing Abby’s voice, it’s as if nothing’s changed. She is the same woman she’s been all these months, firing urgent questions at Sienna, her voice fuelled with concern: When was the last time you saw him? What had he been doing yesterday? Did he say anything unusual?