The American Bar of the Savoy hotel is one long, gently sweeping curve of mahogany. Harriet sits on a high, velvet-cushioned stool, staring at the bright glasses and multicoloured bottles on the shelves behind the barman. They are dining here this evening. A little treat, Ralph has said. He is still trying to make up for the unpleasantness in the garden last month, she knows, although neither of them has ever mentioned it.

She has worn a demure outfit – fashionable, but modest – and is sporting her new rose-coloured lipstick.

‘You choose for me,’ she says to Ralph, twisting her fingers around the pearls at her neck. ‘The only time I’ve drunk cocktails was with Charlotte Gibbs, at the end of the war. Do you remember Charlotte? We were at school together.’

‘Round-faced girl with a dragon for a mother?’

Harriet laughs. ‘That’s the one. Charlotte is a sweet thing. I really ought to pay her a visit –’

‘But not drink cocktails with her?’

‘No. I don’t think so. Do you know, we had the most extraordinary time. I can’t even recall what it was that I drank then – only that I had the most appalling headache the next day.’

She is confident that Ralph understands cocktail drinking far better than she and Charlotte did, barely out of school, ridiculously naïve, sneaking from their homes to share in the great party taking place in London that wonderful night. Harriet had been captivated – and half-terrified – by the hedonism of it. She had watched, wide-eyed and dizzy with drink, as a man and woman grappled with one another in a shadowy corner of the room. They had been oblivious to her, oblivious to anyone other than one another, fumbling with clothing and limbs, juddering and groaning.

That was nearly two years ago. She blinks at the bottles of gin, vodka and coloured liquids in front of her. She is older and wiser now. She is certainly more sophisticated, here for an early evening drink with her fiancé. And this is the Savoy, not the unsavoury bar she and Charlotte stumbled into.

‘Good lord, I shudder to think what two schoolgirls found themselves drinking,’ Ralph grimaces. ‘Probably a mixture of absinthe and engine oil, given to you by gentlemen with dubious intentions.’

‘Yes,’ Harriet laughs back. ‘I think it was something like that. Charlotte was violently ill, so I tumbled her into a taxicab and we escaped back to Kensington. Our parents never found out, thank goodness. It was, for a short time, extremely thrilling – until it became awful.’

‘Sounds like many of the nights out I had as a young man,’ Ralph says, giving the barman a knowing look. ‘Far too many mornings were lost to hangovers at Oxford. A White Lady, Craddock’ he says to the waiting man in the immaculate white jacket. ‘And I’ll have a Manhattan.’

The barman plucks a delicate glass from a shelf and begins to measure out spirits.