This study in sable begins just after the chapter 'Doubt' in The Scarlet Pimpernel, when Chauvelin bids farewell to Lady Blakeney at Lord Grenville's ball, and is my version of what memories and desires really drive the accredited agent. It's not a story, just a perspective. Thanks to Kate and Liz, each a beta-extraordinaire and both fellow fans of Orczy's characters.

Closing his eyes against the gloom of the carriage to better recall the delicious memory, he heard again that low, musical voice pleading with him: "Give me some hope, my little Chauvelin." He saw Marguerite St Just, a vision in rich gold wearing with careless grace her new role of the noble Lady Blakeney, holding out to him a small, white hand: reaching out for mercy. And he had taken that hand because it was the proper thing to do, and Armand, ci-devant Marquis de Chauvelin had sacrificed none of his diplomacy in his zeal for a republican France; he had taken that dainty hand and pressed his lips to the trembling fingertips.

And then, before his gently ironical smile could betray the excitement and mocking amusement building within him, Chauvelin had dismissed the beautiful woman before him without allaying her fears: "Pray heaven that the thread may not snap."

With a final, searching glance over her shoulder, she had then been caught up in a wave of her own popularity, as men of all ages and stations vied to offer her their arm and accompany her to her husband's waiting coach. Chauvelin was accustomed to this repetitive and rather nauseating sight, from the days when he had known citoyenne St Just in Paris; he recognised in these lords and ministers of London society the same breed of men which had once consisted of playwrights and patrons, noblemen and bourgeois merchants – even leaders of the burgeoning Republic. Men of every level of background, wealth and standing, reduced as one to simpering fools before the shimmering beauty of Marguerite St Just.

Alone with his thoughts as he returned to his lodgings, Chauvelin mused over how her allure was certainly greater as Lady Blakeney, wife of one of the richest men in England, and leader of fashionable society. Yet it wasn't material advantage that had honed her charm, he thought: it was a certain maturity she seemed to have acquired, based, he had intuited, in unhappiness. Marriage had brought the glorious Marguerite crashing down to earth, and now she was all the more fascinating in her uncertainty.

As a shadow in the corners of her apartment on the Rue de Richelieu, haunting her little circle of the great and the glorious, Chauvelin had found the young Marguerite St Just to be artificial – beautiful, yes, but her appearance in his eyes had been marred by her awareness of her own charms. Her whole life had seemed to him a continuation of her work on the stage, always playing to an audience until her outward personality had become merely another role.

He had attended her court only because other influential men had done so, using the rooms she shared with her brother as a meeting place in those early years of the tumult in Paris. 'My little Chauvelin', she called him then, playing the coquette with the ambassador as she appeared to hang on his sparse but weighty words. He would feel the light touch of her small hand upon his arm, inhale the warm scent of her perfume, and know that her large eyes were studying his expression, watching his lips move. If his contribution to the debate was applauded by the others, she would beam at him; if met with hesitation or hotly contradicted, a gentle pressure on his arm would be his solace.

With hindsight, Chauvelin prided himself on having been able to see past the autumnal shades of her hair and the liquid quality of her blue eyes, where wiser men had fallen under her mesmerising charms. He had observed her offer the same friendship, attention and flattery to figures who might soon rule the country – including her own cousin, Louis-Antoine St Just – before smoothly placing herself beyond reach of any stronger advances. Chauvelin had been galled, but also intrigued, by the young woman.

And now they were together again in London: he the representative of a republican government loathed by a country still loyal to its king, she the leader of aristocratic society in a foreign land. Upon finally locating her in England, Chauvelin had been pleased to note that citoyenne St Just, as he still thought of her, had not lost her skill of entrancing men and inspiring women: there she was, a French, theoretically republican, former actress, newly married into English society – yet everybody loved her! And, until he had listened harder, picking up on a few whispered insinuations about the mental health of the Blakeney family and the 'talents' of the new lady of the manor, Chauvelin had actually been in awe of this daughter of the republic.

Then he had realised that, as in France, her charm had a limited range, and when the charming citoyenne was not there to dazzle and entertain, her admirers were able to remember that she was only human. Without her large blue eyes holding their gaze, or her salon wit to amuse them, her power was lost. She became a usurper – a foreigner, a player, a threat. So she was attractive – isn't that after all why Sir Percy must have married her? He had thought Blakeney to be just another fool with too much money and not enough sense – it was apparently well known that he was none too bright – and she a very experienced actress from the French stage: Blakeney's thoroughly English noblesse oblige had probably made him offer marriage where others before him had escaped such a hefty toll.

All this and more had Chauvelin heard about the new Lady Blakeney, when he had actually taken the trouble to listen. And it had been with such a dossier that he had confronted her in Dover, letting her imperiously mock and then turn away from him, but his power over her had grown little by little, until now he held her completely, about to betray her husband to save her brother. The unsuspecting dupe! She was completely unaware of the gravity of her actions, which was the beauty of the situation – but also the disappointment – for Chauvelin. She couldn't know, because, as he himself had been up until the meeting in Grenville's dining room, Lady Blakeney was also ignorant of her husband's secret. She thought she had fulfilled her side of the bargain, maybe, but she didn't know what that entailed, or whom Chauvelin had encountered on the basis of her betrayal. The innocently hopeful look on her face, her conspiratorial whispers on the staircase, her trust in him to do right by her brother – and all the time … Chauvelin bit down on his lower lip in a private, twisted sneer of amusement. The irony appealed to him – Lady Blakeney had just satisfied the worst of the rumours about her marriage, and handed her golden prize over to the enemy.

As his coachman navigated the narrow streets of the city, Chauvelin remembered Lady Blakeney's earlier defiant speech to him, and how he had taken her words at their petty value: "we ladies think of him as a hero of old … we worship him … we wear his badge …" She had meant to show him, as she stood beside her appreciative Prince, that not even Armand Chauvelin could trouble her now; she was above judgment and beyond scorn. But without her husband, what then?