‘I’ll watch too,’ said Marnie quickly. Her palms suddenly felt clammy, her heart had started to thump and the old familiar screw of fear was twisting in her stomach, the reference to tribal customs setting sinister shadow figures of other carnival dancers leaping through her brain and the fearsome masked face of the Jab Molassi peering into her soul.

‘No chance,’ said Giles firmly, completely unaware of the demons he was releasing. ‘Everybody takes to the floor and you’ll both be fine. We’ll start with something really easy and then once you’ve got the hang of that, we’ll have a go at an eightsome. Apart from Louisa – who’s been doing it since she first learned to crawl – have any of you danced a Dashing White Sergeant before?’

The Colonel and Christopher both said they knew how to do it.

‘Wonderful,’ said Giles. ‘That’s a great help.’

Marnie, checking how near she was to an exit, started backing to the edge of the room, the ringing in her ears so loud she thought everyone must hear it too – hear the beating of drums and the wild shrieks – but most people’s attention was fixed on Giles as he showed the visitors how to do a basic pas-de-bas step and then gave a demonstration with Isobel of how to set to a partner.

Keep breathing. Unclench your hands. Concentrate on something else . . . the voices of various therapists also rang in Marnie’s ears. Don’t let anyone notice me, she prayed, unaware that Christopher had unobtrusively followed her to the door.

‘Now please form threesomes,’ Giles was saying. ‘It doesn’t matter if it’s a man with a girl each side or the other way round – and stand facing another three. I’ll call out what to do while you pace it through once and then we’ll have a go to the music.’

Christopher quietly reached for Marnie’s hand and hung on to it. ‘Dance with me?’ he asked, smiling at her in a way that in other circumstances would have made her heart turn over, rightly guessing that she was about to bolt from the scene – recognising the signs of a condition that, since his car crash, he knew all about too. ‘Please dance with me,’ he said. ‘I promise I won’t let you go wrong. Don’t look so panic-stricken. It’ll be all right.’ He drew her back into the room where Louisa was standing talking to a friend of the Grants. ‘Come on, Louisa,’ he said. ‘Will you do this with us?’

‘Of course,’ she said, privately thinking it extraordinary that a light-hearted social activity could cause anyone to look as scared as Marnie did – like a rabbit caught in the headlights of an oncoming car, she thought: Marnie at her plainest and least attractive. Louisa took Christopher’s other hand.

‘We’ll make a threesome then,’ she said. ‘Let’s go and dance with Izzy.’