‘OK,’ Sadie says slowly, and she starts to repeat the story of how there was a storm brewing, both weather-wise and at the party, that Caro was wearing a red, ruffled dress with exquisite diamond stud earrings, that she and Rupert had rowed.

‘What about?’ I say, leaning forward and resting my chin on my hand. ‘What was the row about?’

‘Well, I don’t know.’ Sadie blinks. ‘No one could actually hear them arguing, it was all hisses and whispers.’

‘Didn’t you ask Rupert?’

‘Well, I might have mentioned it to him afterwards, before we realized what she had done. He couldn’t really remember, he said it was just about nothing really. It’s what Caro was like – part of her liked the drama.’

I sit back, piecing together what Sadie has told me so far. ‘So, Rupert and Caro rowed about something – something insignificant, according to Rupert – and Caro stormed out of the house. Then… what? No one saw her alive again?’

‘Yes.’ Sadie looks away, rummaging in her handbag for a tissue that she holds to the corner of her eye. ‘Rupert called me the next morning to say she hadn’t come home, that her car was still gone from the garage. We were all worried, of course we were, but she’d done it before, flounced off and then come home days later as if nothing had happened. She’d tried to commit suicide before too, but only ever at home.’ She raises her eyes to mine and grief is etched deep into her features. ‘None of us realized that she would… that she had done it for real this time.’

‘I’m sorry, Sadie,’ I say, reaching forward to squeeze her hand, ‘I’m just trying to get things straight in my head. So, after a few days Rupert called you to tell you what the police had found?’

‘Yes.’ She blows her nose delicately and sits up straighter, shaking her fringe out of her eyes. ‘Rupert called and said that the police had found her car close to the Severn Bridge. There was a note on the passenger seat that just said “Sorry”. It was clear that she’d gone through with it this time. It was utterly devastating, but I’m afraid to say it wasn’t really a shock to those of us who knew her well.’

‘But they never found her body?’

Sadie stiffens slightly. ‘No. They never found her. The police told us she would never have survived the fall, and that the currents can be so strong that she might never wash up. We held a memorial in her honour a little while before Rupert met you. She’d been gone for a year by then.’

I nod slowly, trying to match the puzzle pieces in my mind. A flicker of excitement burns in my belly and I have to think through what I am about to say, conscious that I might make things worse.