Cally had never, ever in all of her life, felt nerves like she did the moment she took her place in the receiving line on the night of the masquerade ball—she felt picked apart, as if the pins and needles holding her costume together were falling out and she was unraveling at her seams, when in fact her patch-color Columbina costume fit her to perfection.

But still, she was as anxious as a tethered racehorse—there were so many details, so many particular things they had had to arrange, so many possibilities for things to go wrong—she could barely stand still.

“Ready?” Tobias McTavish appeared by her side attired in his own form-fitting costume.

Cally took a deep breath in admiration of the magnificently honed body the motley revealed. “Gracious, McTavish. I am as ready as I’ll ever be, though I think I should check to make sure there are adequate chaises in the withdrawing rooms, so the ladies can recover after ogling you.”

He laughed just as she had hoped, dispelling some of her tension. They had spent the previous day in close consultation, working out the details of the roles they were about to play, but the worry—the constant imagining and reimagining all the possibilities—had been exhausting. Cally had hardly slept a wink.

But she forced herself to smile, and be her normal self. “You do look exceptionally fetching in your costume, sir.”

“Let us hope I do—and can fetch both the jewels and my reputation back this evening.” Then he took her hands and spread them out before him, to inspect her costume. “You on the other hand, look stunning. If you were to take up thievery you’d be able to rob men blind just by smiling at them in that costume.”

“Thank you, Toby. I’ll take that as a compliment.”

He leaned in to whisper. “I mean it as such.”

Before he could kiss her, Mama was in the corridor. “Come along, children.” Her mother waved her mask upon a stick to magic them into place before the ballroom doors.

Together they looked magnificent—all hot patches of bright harlequin color that presented a united theme. Toby was all but unrecognizable as their equally masked and turbaned servant in harlequin, bearing an enormous feathered fan to shade and cool them, despite the fact that it was ten o’clock at night. And inside. And winter.

But masquerade balls were not at all about reality. Cally could only hope the fantasy they had spun would do its work.

“Assume that nearly every man without a partner will be a Runner,” Toby whispered at her back. “It will be your job to keep their attention.”

They had worked through her step-father, Viscount Balfour, and his son Arthur to give the constabulary what purported to be a tip-off about the ball. The viscount had hired the Runners himself, saying that he wanted the extra protection of Bow Street’s men to ensure his guests felt safe—Bolter’s death notwithstanding, society as a whole was still nervous of theft.

And even if Toby had no confidence in the Runners’ ability to catch the thief, he needed them to witness it when he did.

The viscount followed his wife, nodding to each of them in turn. “Are we all ready, then?”

Cally smoothed her skirts over her nervous tummy. “I think I know now how they must feel on the stage at Drury Lane, just before the curtain goes up.”

“Break a leg, they say to one another,” Toby laughed.

“Oh, lord, no.” Cally wouldn’t hear of it. “Please don’t break a thing.”

“I pray you will take great care not to break anything,” breathed Mama before she clasped Toby’s hand. “But let us hope the best man indeed wins.”

And so it began, with costumed guests making their way into the house as if it were all choreographed by an unseen hand pulling their puppet strings.

And with those guests, a number of unaccompanied, costumed men made their way into the ballroom without the benefit of being announced, while Cally and her mother greeted and exclaimed over the cleverness and imagination of their invited guests.

“Aren’t you all quite the pretty family group,” more than one wag offered. “And so convivial, your beautiful daughter and your handsome step-son.”

“Oh, that’s not Arthur,” Mama began disingenuously. “Poor boy, always called away on some important business. This is—”

And then Cally would interrupt and whisper, or stop Mama with a quick jab of her fan, or speak over her. “How lovely to see you this evening, Your Grace. That plume in your turban— simply the limit! You must tell me how you contrived it. So original and fetching!”

And on and on they went, greeting after greeting, until at last all the guests were assembled, and the family themselves were about to be announced.

“Oh, gracious!” said Mama in a voice that carried well into the ballroom. “I forgot my fan. Cally, do be a lamb—”

McTavish stepped conspicuously forward. “Let me play my part and fetch it for you, Viscountess.”

“Oh, Toby. Thank you, you’re most kind.”

“Mama! You shouldn’t have said his—” Cally cast what she hoped was a horrified glance toward the ballroom, where the guests suddenly found they had much to talk about behind their own fans.

And several of the hired footmen in their dark livery from the wine merchant moved from their positions along the walls to speak to one of the lone gentlemen in consultation. After a moment of conference and gesticulation two unaccompanied fellows followed Toby out.

Perfect.

Cally whisked a glass of champagne from the nearest tray. “Here’s to success in bold ventures.”

Mama took her own glass, and returned, “Here’s to you getting your heart’s desire, and not getting your heart broken,” as she entered the ballroom as if nothing were at stake.

Cally gulped down the wine. She didn’t want to think about what might happen if it all went wrong—if even one thing went wrong and their plan began to collapse like a flan in a cupboard.

But in another minute her harlequin was back, handing Mama her fan with a courtly bow, and it was time for Cally to act—she went on tiptoe to whisper into his ear as if she were telling him about her mama’s slip-up.

He shrugged, as if the mistake was of no account, and then offered his hand in silent compensation.

“Oh, yes.” Cally gave him a smile as if she might make up for the error by lavishing him with all her attention. “I’d love to dance.”

And so they did. The moment Mama signaled for the players to start, Cally led her harlequin out onto the dance floor where they remained, dance after country dance—with the exception of one short break for the supper at midnight—for the entirety of the ball.

On and on they danced as the others came and went, until at last they were the only pair on the floor, and the musicians finally stopped playing.

Mama had somehow already retired for the evening—it was only the servants from the wine merchant and those loose, unattached men still propping up the walls.

But Cally pretended she had eyes for no one but her partner. “Come,” she whispered just loud enough for every last Runner in the house to hear. “Everyone is gone. Come with me.”

She led her harlequin slowly by the hand out of the ballroom, up the grand staircase, and to the door of her room, where she gave her darling swain her best smile for the benefit of the Runners who had not-so-surreptitiously followed them, and quietly took him into her room, and locked the door with an audible click.

Whereupon poor Arthur Balfour pulled the masque and turban from his head and collapsed into the nearest chair. “My God. I’ve never danced so much in all my life.”

“Nor I,” Cally agreed. “And let’s hope we never have to again.”

They had done their part.

The rest was up to Toby.