‘My dear Lady Allenham,’ he sighed, ‘I believe you will find Madame Bonet’s establishment among the most reputable in this quarter.’ Then, to prove its credentials, he took from the box of books at his feet Mr Nugent’s Grand Tour and pointed to the author’s commendation of it. I peered up at the Hôtel l’Impératrice through the window. Although largely obscured by shadow, it seemed a tidy enough place; its whitewashed edifice was adorned with neat black shutters.

There seemed nothing irregular in the manner of its squat proprietress or in her army of footmen. She had come in a hurried manner to greet us, her chatelaine of keys bouncing at her hip. Immediately she fell into a curtsey worthy of the halls of Versailles.

‘Madame Allenham,’ she pronounced. ‘Monsieur Savill sent word from Saint-Quentin that you would be amongst his party.’

I cannot imagine what nonsense the Irishman had written to her of me. Whatever the case, she seemed as convinced of my rank as he, and for my clever deceit, I was now to pay dearly. With a gracious smile, Madame Bonet led me up one pair of stairs and I was ushered into the Hôtel l’Impératrice’s finest set of apartments.

Each room was unlocked before me, like the drawers of a treasure cabinet. The footmen moved hastily about with their tapers, lowering chandeliers and setting light to the wall sconces. From beneath their light a wealth of riches was revealed. There were gilt furnishings and clocks, Sèvres porcelain, Chinese vases and vast canvases upon the walls: still lifes and Madonnas, and pious saints upon their knees. The proprietress continuously nodded and smiled, and occasionally searched my expression for approval. I offered her nothing in return but aloofness, which I hoped masked my disquiet.

I was shown two dressing rooms hung with Gobelin tapestries, a white-panelled dining room with ornate gold architraves in addition to two bedrooms and antechambers:

‘For your maid, madame, and for your husband’s valet . . . when Monsieur le baron Allenham joins you here.’ Madame Bonet took me through each door and only once she was content that I had studied each gold pier table and gilt door handle did she turn to me. ‘I do hope the rooms are to your taste, Madame Allenham?’

Mr Savill, who had stood beside me throughout, peered at me with anxious anticipation.

My expression did not move.

‘Why yes, yes, madame. I thank you kindly.’

What other response might I have made? I was an impostor who had played for high stakes with a poor hand.