At that moment, in a clatter of drums and triumphant tenor horn, the band brought its song to a close – and Archie Adams himself was on his feet, taking appreciative bows from the dancers on the ballroom floor. Raymond, his arm still around Grusin-skaya, watched Vivienne reach forward, pure hatred in her eyes, and – trying to snatch at the young lady’s arm – topple into the table instead. Dazed, she tried to pick herself up. A crystal glass tumbled, shattering onto the floor. More heads turned their way. A waiter, summoned by the disturbance, rushed to clear up the mess, while another disappeared into the shadows on the edges of the ballroom, no doubt searching for someone to come and guide poor Vivienne away.

Vivienne picked herself up. The girl at the table was trying to stand – but the sleeve of her dress was tight in Vivienne’s fingers; she was held fast. ‘You oughtn’t to be in Daddy’s ballroom!’ Vivienne crowed. ‘You’ve no right! Don’t you know your . . .’

Now that Raymond saw her properly, he supposed that the lady did look out of place. The gown she was wearing did not seem entirely of a piece; it was as if somebody had taken two gowns and stitched them together. It was pinched at the neckline, and the fabric worn. Even so, it suited her in an unusual way. She had a pretty, round face and big, dark eyes, and in the dark curls of her hair she was wearing a silver pin that dazzled in the chandelier light.

‘Mr de Guise, you are a gentleman?’

Raymond was distracted. ‘I am, Grusinskaya.’

She leaned forward and whispered, throatily, into his ear. ‘Then go to Miss Vivienne, you fool.’

Raymond left Grusinskaya on the dance floor and weaved his way through the other dancers to the table where Vivienne was unsteady on her feet.

‘Mademoiselle,’ Raymond began, ‘are you hurt?’

Vivienne turned on Raymond. ‘Don’t touch me!’ she slurred. ‘Don’t you know what she is? Why, when my father finds out . . .’

Raymond stepped back. The young lady was already on her feet. Eyes followed her as she fled. Somewhere, somebody sneered. Somebody else roared with laughter, for dramas like this were rare in the Buckingham ballroom.

At that moment Mr Simenon, the head concierge, arrived to lift Vivienne back into her seat. She had drunk too much tonight, that was evident. But as she lolled there in her chair, the band sending out the first shrill blasts of a new song, Raymond saw that her eyes were adrift. They had a peculiar, glazed quality. She was having to concentrate to remain upright – and that, thought Raymond, could not merely be the after-effects of the Dom Pérignon she’d been drinking by the glass.

‘Mr de Guise,’ Mr Simenon began, in his slick, slippery voice, ‘I may need some help.’