Ben’s house sat at the end of a gently sloping gravel driveway, bordered by immaculate shrubs and fruit trees. An ornate ivory-painted birdhouse stood on a tall pole halfway up the drive. There were two cars: Beth’s silver Mercedes estate, and another of Ben’s cars, a white convertible Audi TT. All his cars were white. The house itself was huge, a three-storey Edwardian family home built when six kids was the norm and servants lived on the top floor. Additions over the last century had included a tennis court, games room and conservatory big enough to seat twenty. As was the way of things, even as family sizes had grown smaller the house grew bigger still: the Delaneys – who had just one child – had owned it barely a year and were already busy with plans to extend it further.

Watching from the street, I saw the front door open. Beth emerged, slowly, holding something in both hands out in front of her – an upturned pint glass, face down on a postcard. She knelt by the flowerbed beneath the bay window, lifted the pint glass and tapped the postcard gently. A spider. She knelt for a moment longer, then stood up and went back inside the house.

Gravel crunched beneath my feet as I walked up the driveway. The doorbell chimed with old-fashioned tones, echoing in the rooms beyond. I waited and was about to press it again when Beth opened the front door, her weary look quickly turning to surprise when she saw me on the doorstep. She looked beautiful – she pretty much always looked beautiful – but she wore no make-up to disguise the paleness of her face. She never wore make-up. Like she never did bright colours – always calm shades, soft tones.

Beth Delaney had always believed in the fundamental goodness of people. But her expression suggested she’d just discovered a different truth, and it had tilted her world on its axis. I felt hugely sorry for her.

‘Oh,’ she said in a small voice. ‘It’s you.’

‘Can I come in, Beth?’

She hesitated, looking past me down the drive.

‘What do you want?’

‘To talk.’

‘About?’

‘Ben.’

She pushed the door almost shut and I heard the rattle and click of metal sliding into place. When the door reopened again a thick brass chain stretched across the gap.

It wasn’t surprise on her face – it was fear.

‘Why did you come here?’ she said. ‘To our house?’

‘I thought it would be easier to talk face-to-face, rather than on the phone.’

‘The police were here again this morning,’ she said. ‘Asking about Ben and that woman.’

‘You mean Mel?’

‘She lied about you and Ben falling out on Thursday evening.’

‘She lied about a lot of things.’

‘The police said you had a fight with Ben, you hurt him.’

‘He’s trying to set me up, Beth.’

She frowned and stared hard at me.

‘What do you mean? How?’