Vivienne glanced up at her stepfather briefly before she whispered, ‘I should think a lady in my position could. Are you a proficient dancer?’

‘More so than these fine gents.’ Nathaniel’s father gave him a look like daggers, but Nathaniel himself seemed undeterred. He straightened himself, brushing his long fringe out of his eyes. ‘I demonstrated dances at the Imperial for a summer when I was nineteen. That was until my father over there – Oliver White, he goes to the same club as your father – decided it was too uncouth. A dancer in the family he could tolerate – but a dancer at a seedy little place like the Imperial?’ Nathaniel threw his head back. ‘The shame!’

Billy knew of the Imperial. It wasn’t unheard of for him to scurry through there on some errand or other. The pages there thought him an aristocrat himself, and all because he walked the corridors of the Buckingham. The Imperial might not have been as opulent as these surroundings, but it was hardly a hostel for degenerates. The ballroom there had hosted the Tommy Dorsey Orchestra. They had a Friday night cabaret and a continental kitchen where the finest French cuisine was served day and night.

‘Do you dance, Miss Edgerton?’

Billy watched Vivienne’s eyes light up. The elder men were engrossed in conversation – he heard only snatches, talk of the Mitfords who held society in the palm of their hands, the name of Mr Chamberlain, the Chancellor – but Vivienne sidled closer to Nathaniel.

‘I’ve . . . been known to dance a little. The ballroom after dark, it’s like . . . It’s positively enchanted.’ Vivienne stopped. Her eyes, which had been focused so intently on Nathaniel, flicked up – and, like two stage spotlights, they found Billy Brogan in their glare. ‘Billy,’ she snapped, ‘haven’t you a little something for me?’

Billy felt as if he was pinned to the glistening floor. The rumbling conversation of Lord Edgerton and his guests petered into silence. Lord Edgerton himself turned to consider him through his spectacles. Invisible, he thought. Pages and porters, chambermaids and valets, we’re meant to be invisible.

Across the Queen Mary, the change in atmosphere must have been noticed, because all of a sudden Mr Simenon and the head waiter reappeared. Abreast, they marched across the restaurant as if they were knights on white chargers rushing to some damsel’s defence.

‘Can we help you, young man?’ Lord Edgerton intoned.

‘Brogan, what are you lurking for?’ Mr Simenon breathed.

‘I . . .’

Mr Simenon threaded his arm through Billy’s and, gushing out apologies, swept him aside. He whispered, ‘Are you simple, Brogan? Deliver the package to Miss Edgerton’s suite, not directly to her. Were you truly thinking to deliver it here, in front of her father? You Irish are bog-brained, Brogan, but I expected better of you! Off with you, boy! Don’t let me see you here again.’