Her memories of family life before the murders had become faded, like a blanket that had been washed over and over again until the colour had disappeared and the edges were frayed, no scrap of comfort left in its thin folds. She had her own family now. That was enough.

Catherine turned off the tap. Her thumb stung, a physical pain rather than low-level anxiety, her constant companion. She welcomed the distraction.

From the kitchen window, she could see her back garden. The snow had covered the grass and the roof of the summerhouse, and was falling steadily. If it carried on at this rate, there would be a couple of inches by lunchtime. She wondered if they would close Honor’s school. It didn’t take much these days.

The telephone in the hallway began to ring. A brusque sound, it startled her. Nobody used the landline these days except cold callers. She had meant to cancel it but had never got round to it.

‘Hello?’

‘Mrs Allen?’

‘Yes, that’s me.’

‘I’m calling from the office at Sweetwood.’

She recognized the voice. How strange that a moment ago she was thinking of Honor’s school, and here was one of the receptionists, Mrs Samuels, on the other end of the line.

‘Is Honor unwell today, Mrs Allen?’

Even though she knew the answer, Catherine paused, as if the break in time might alter the implication of that question.

‘No, she’s – I mean, she was fine at breakfast.’

‘It’s just that she hasn’t registered this morning and we wanted to confirm the reason for her absence.’

Catherine’s stomach performed a slow-motion roll. At once, a series of scenarios began to play out in her mind, each more devastating than the last. Truancy. A hit and run. Abduction by a stranger in a car. With her family history, catastrophizing was second nature.

‘She left home at her usual time.’ Catherine’s fingers tightened around the receiver. ‘She’s never missed school before. Something must have happened.’

‘Perhaps she had an appointment she didn’t tell you about.’

‘She’s twelve,’ said Catherine. ‘She doesn’t have appointments I don’t know about.’

But a fissure of doubt opened up.

‘Well, you might want to give her a call on her mobile,’ said Mrs Samuels briskly. ‘The forecast is for more snow. Mr Lexden is thinking about sending pupils home at lunchtime. I’d hate her to turn up when everyone else has left, especially in this weather. Please do let us know if you track her down.’

The nerve above Catherine’s lip began to twitch. It did that when she was stressed. She pressed the tip of her finger to it until the spasm stopped and tried to formulate a plan.

She checked her mobile to see if Honor had texted or tried to call, but there was nothing except a junk email about final ordering dates for Christmas hampers.