Effie made her way carefully to the other end of the chaise. Now that she’d had a moment to get her bearings and adjust to the grand surroundings, she was beginning to absorb the finer details – William was standing in a corner holding Margaux on a lead. The big cat was sitting up and panting, perfectly docile, but the footman’s eyes kept glancing towards his charge every few moments, as though he was taking nothing for granted. If she hadn’t been so terrified, Effie might have laughed at the sight.

Mr Graves, too, was there. He had been standing by a drinks table and now approached with a tray and a bubbling glass upon it. ‘Would you care for some champagne, Miss Gillies?’ he asked, his eyes meeting hers briefly. Only a few hours earlier she had been sitting beside him, eating mutton.

‘Thank you,’ she smiled, taking the champagne even though she had no intention of drinking it. Fanny had fiercely warned her about this too. ‘It’ll make your head fuzzy and the room swimmy. You’ve not got the stomach for it, not if you can’t keep down a steak and kidney pie. Just pretend to sip it.’

Sibyl, on the other hand, drained her glass, tipping her head right back before holding out a straightened arm for a refill and sending the butler back to the drinks table again.

‘Miss Gillies, I must confess I would not have recognized you from our meeting yesterday. You’re an entirely different creature. You look simply divine,’ Sibyl said. ‘Who’s your couturier?’

Effie stared at her blankly.

‘Only I swear I’ve seen that gown before. A dear friend of mine had one awfully similar. Nancy? Nancy Mitford?’

Effie felt the shame bloom in her cheeks. She had been in the room all of a minute. She hesitated, wondering what to say. Fanny hadn’t coached her for this eventuality. ‘Yes,’ she said finally. ‘I believe this was hers.’

There followed a silence that seemed to be one part appalled, two parts delighted. ‘You mean . . . the very same dress? The actual one? But how could that possibly be?’

She swallowed. There was nothing for it but to come clean, lest Sibyl should run away with the even worse assumption that the dress had been stolen. ‘I’ve borrowed it for the evening, from Barra. Miss Mitford gave it to her when she left her service.’

Sibyl’s mouth opened wide. ‘Oh! Oh that is too fabulous. Just wait until I tell her I’m having dinner with her dress! She’ll scream! She’ll die!’

Effie was alarmed. She sincerely hoped not.

‘I wouldn’t,’ Sholto said, motionless at the fireplace. ‘It would only upset her to hear that Miss Gillies looks supremely better in it than she ever did.’

Sibyl’s mouth snapped shut, her little joke abruptly falling flat. Effie shot him a grateful look but he had already looked away.