Every now and then, as he spun around, Collis glimpsed Grant’s glowering, unhappy face, as he stood there with his arms by his sides and his lower lip stuck out, waiting for the quadrille to end.

On the last chords of ‘La Pastourelle’, it eventually did. One of their partners, a small round Moravian woman in a diamond choker, was gasping and panting, and her husband had to support her. The younger couple gave a nervous smile and disappeared at once to find sherbets and lemonade. Collis was left alone on the floor with Sarah, and he reached out his hand to her and said gently, ‘Will you take some refreshment? We’ve been dancing all this time and we haven’t spoken a word.’

She came towards him, her silk skirts and underskirts rustling. ‘Do you have to speak to let people know what you think?’

He gave a small shake of his head. ‘Not with people like you.’

She held back her hand at the last moment and raised an eyebrow. ‘I didn’t know there were any people like me.’

‘One or two. But none as beautiful.’

Suddenly Grant came up and stood right in front of Collis, with his hands on his hips and his face looking bigger and more boiled than ever.

‘I’ve just spoken to my father about you, Mr Edmonds. He says you’re to leave Sarah alone, please, with his compliments, and why don’t you go dance with someone your own style.’

Collis raised his hand. ‘There’s no need to bark, Mr Melford. You can see that I haven’t abducted your sister, nor seduced her. She’s here, safe and sound, and smiling of her own free will. She’s danced with me once with no apparent ill effects, and if she wants to dance with me again, then she will.’

‘Not if I can help it.’

‘You can’t,’ said Collis.

‘What if I belt you in the nose?’ demanded Grant.

Collis slowly let go of Sarah’s hand. He felt suddenly cold, and he could feel the sweat of the dance under his armpits. If there was one thing that angered him beyond the point of coherence, it was the threat of assault. He wasn’t particularly brave, and in most confrontations he would rather back down than risk a black eye. But young college greenhorns who thought they could frighten him with bluster and bunched-up fists were something else. They needed what his friend Henry Browne used to call ‘the lesson that the rooster taught his eggs’.

Sarah sensed the change in Collis’s demeanour. ‘Grant,’ she said, a little breathlessly, ‘it’s all right. We’ll only have one dance more.’

‘Father won’t permit it. And neither will I.’ He kept his eyes on Collis, and his lower lip firmly stuck out, like the bottom drawer of a bureau.

Collis looked at Sarah, and gave a weary shrug. ‘Well,’ he said, ‘I suppose we must honour your dear brother’s wishes. He seems to believe he has your best interests at heart, in a bovine fashion.’