‘A Christmas card, I guess. I found it on the doormat.’

Beth turns to face Simon, and hands him a glass. She takes a large sip from her own, savours the rich fruity wine as it trickles down her throat, then picks up the white envelope. Her name is written in capital letters. BETH. The flap isn’t stuck down, but it looks used. She pulls the card out.

Except it’s not a Christmas card.

And it’s too late to hide it from Simon.

FEELING GUILTY YET, BITCH?

I’M WATCHING YOU …

Big letters, scrawled in black Biro.

She drops it onto the white quartz, can’t stop a gasp flying out of her mouth.

‘What the fuck?’ Simon grabs it – not a greetings card at all, just a ripped-up section of Pret sandwich packaging in a used envelope – and lifts it towards his face, as though hoping it will read differently at close range. ‘What’s this about?’ he demands when the message doesn’t change. ‘Who would send you this?’

Beth shrugs, tries to smile, but the air around her is too heavy, weighing down the corners of her mouth. ‘I don’t know,’ she whispers. The words slide out slowly, but her thoughts are faster. The note has to be from Mark; did he follow her last Friday and find out where she lives? What should she tell Simon? He knows about Mark – DC Stone told him what happened outside the shop when the detective dropped Beth home – but he accepted her assurance that it was nothing to worry about, and he doesn’t know about the squatter appearing on Friday afternoon. Will he want to call the police? She couldn’t bear that. She needs this whole ugly event to be over, finished, not evolving into something bigger and more awful.

‘Hang on, you don’t think it’s that homeless kid, do you?’ Simon says, invading her thoughts, his face screwing up in disbelief. ‘The one that shouted at you outside that squat?’ He shakes his head. ‘If he’s still angry ten days on, there is something seriously wrong with him. We should call the police.’

‘No, I …’

‘He’s dangerous, Beth.’ Simon pauses, realisation creeping over his face. ‘And he knows where you live. Christ, he must have followed you.’ He pushes off the stool and starts pacing up and down the length of the island unit, sweat beading on his forehead. It’s funny to see the fear that has lived inside Beth since that night, secret and shapeless, become something tangible as it spreads to her husband.

At least the girls are oblivious, Beth thinks. She imagines them cuddled up on the sofa in the playroom watching The Snowman; she can hear the familiar music as it slips under the closed kitchen door. The image calms her. Her children are still blissfully unaware that bad stuff ever happens; she’s achieved that at least.