She’d have gladly left them all and let them bear each other’s company without her interference, but she had a part to play, and with the younger of the frilly sisters gone upstairs she knew her role was even more important to the plan they’d laid in place.

“Your brother,” Stevens said to Mary with the faintest stress upon the second word, “has chosen a good drink for us. Do tell him I am grateful.”

Mary gave a nod to show she understood, and translating his words to French she passed them on to Thomson who was sitting to her left. Receiving Thomson’s brief but courteous reply she turned that into purposely imperfect English, telling Stevens, “He is very happy you are thinking this, monsieur.”

She saw a mingling of amusement and acceptance in the Englishman’s expression, as though he meant her to know that he knew well this whole performance was unnecessary. “Tell me, mademoiselle, how is it you speak such good English while your brother knows it not at all?”

She borrowed from a story she’d invented once at bedtime for her cousin, and adapted it to give herself the background of the heroine. “Ah, is very sad, monsieur. Our parents, they are dead when I am very young, and so my brother has to take the business of our father, but he has no one to care for me, so I am in the convent placed. And in the convent,” Mary said, “a nun from Ireland was, who teached me English.”

“Did she really?”

“Yes.” She hoped he did not ask her where the convent was, because she did not have a ready answer. In the fairy story she’d created, it had been in a far-off and magic land without a name, but she could hardly use that portion of the tale. “But in a few years all is well again. My brother came.” The best thing about telling stories, Mary thought, was that one could reshape them as one wished, and change the ending to a happy one. “He takes…he took me home.”

“And where is home?” asked Stevens.

Mary faltered, but her tiny pause was neatly covered by the fact the Scotsman chose that moment to excuse himself and stand and leave the room, which actions proved enough of a distraction to the Englishman that Mary gained the time to call to mind the birthplace of that famous authoress she so admired and whom she sought to emulate: Madame d’Aulnoy. “Barneville-la-Bertran,” Mary named the little village in the north of France and trusted it was small enough that Stevens would not know it.

To her great dismay the merchant said, “Ah yes, I know this place.” He turned to Stevens, and in English added, “It is near Honfleur, in Normandy.”

“I see.” And letting his gaze slide with seeming nonchalance from Mary to the man beside her, Stevens said to Thomson, “And what is your business, sir?”

She held her breath. She almost dared not look at Thomson, fearing he would fall into the trap that had been set for him by answering in English, as he’d done before by accident, or simply by revealing he had understood the question. He did neither. With a faintly puzzled frown, he shrugged and looked to Mary, asking her in French, “What did he say?”

She breathed, and felt a mingling of relief and admiration that she smothered as she might have snuffed a candle flame, reminding herself stiffly that however kind and charming she’d found Thomson, he was not a man to be admired. He was a fraudster.

If she shielded him now it was only because she felt bound by the pledge she had given Sir Redmond: he’d asked her to help and she’d told him she would, and whatever else happened she would not go back on her promise. Her word. She’d have little else left of her honor, she knew, if the identities and crimes of her companions were exposed. Her safety now was tied to theirs—if they were caught, there would be none who would believe she was an innocent accomplice. And by joining in their plan tonight, she knew she’d lost the right to claim full innocence.

She fixed the mask—invisible to all except herself—across her features and began to translate Stevens’s last question for the benefit of Thomson. She had barely made it halfway through before the Englishman’s attention was again diverted, this time by the calmly self-assured return of the tall Scotsman.

He was carrying the leather case he’d carried out of Paris—the long cylinder he’d stowed each day atop the moving diligence. The case itself was interesting. It had been made to open not along its length but round its middle, and not hinged but merely fastened on with straps and buckles so the whole top half could be detached and lifted off and set aside. He sat and did that now, revealing to them all the long and polished barrel of a gun.

“Ah, yes,” said Mary, breaking off her speech as though she’d only just remembered. “Yesterday I tell my brother how you like to speak of hunting, and he thinks you might enjoy to see the gun señor Montero brings from Spain.”

MacPherson had the gun out of its case now, holding it vertically balanced with one strong hand. Mary knew nothing of guns, beyond their basic structure and their function, but she didn’t need to look at Mr. Stevens’s face to know this one was special. A thing men would covet. It was handsomely made of some richly dark wood, with an ivory-tipped ramrod and fine engraved scrollwork in silver and gold, and an elegant guard to the trigger.

“May I?” Stevens stretched a reverent hand towards it, and MacPherson passed it over, looking on with an impassive face as Stevens stroked one hand along the piece and said, “It has been rifled, also. Here,” he told the merchant in the manner of a man compelled to share a great discovery, “see these spiral grooves that have been cut within the barrel? These do place a whirling action on the bullet so it spins upon its axis in its flight and so does bore the air as keenly as a screw, and travels straight and true and with prodigious speed. I have heard tell of these,” he said, “but never seen one.”