For the first time in her adult life, Constance found that she had been left to her own devices.

Wolfgang was still away on business; meanwhile Josepha had managed to sweep the rest of her family up in the excitement of being cast in an opera that would play at the emperor's festival in two weeks, and Aloysia was busy with the opera that Nannerl and her order would be putting on in secret. Constance sat in on their meetings sometimes for lack of anything better to do, but couldn't bear to stay for long. The music Nannerl composed at the organ was haunting, and she had managed to scribble down dozens of melodies, but every day that they went without a libretto their rehearsals ran a little shorter and the look of impatience on Aloysia's face became a little harder to ignore.

One night, Constance decided not to descend into the catacombs at all. She retrieved Wolfgang's leopard-spotted coat and a pair of his breeches from the back of her wardrobe, twisted her hair up beneath one of his hats, and she set off alone in the direction of the mollyhouse ballroom.

The dance was still going on as it always was, as if nothing had changed. Constance half-expected to see Wolfgang's lavender coat weaving in and out among the guests, though the awkward, shrill tune being played on the violin in the corner was as good an indication as any that her husband was not here tonight. She dropped into her usual bench with a sigh, leaning her head back against the wall. Maybe she would finally accept a masked stranger's invitation to dance tonight. Maybe that would be the distraction she needed to quell the dread that had been slowly building in her chest for weeks, for months, even since the day the emperor had announced that he was having Figaro withdrawn. Ever since the day the light had gone out of Wolfgang's eyes. Since the first time he had looked at her like he didn't know her at all.

"Herr Conrad!"

Constance's head jerked forward at the sound of the familiar voice, and she sprang to her feet when she saw who had greeted her. "Herr Stephanie!"

Wolfgang's former librettist looked just as he had the last time she had come here with Wolfgang, even wearing the same blue jacket. Constance couldn't help but notice that the elbows had gone a little shiny. She averted her eyes, grateful to her mask for hiding her pity. Poor Herr Stephanie's work had fallen from the emperor's favor even before Wolfgang had begun work on Figaro. How long must it have been since someone had commissioned a libretto from him? "I'm delighted to see you again!" Herr Stephanie was saying, dropping into one of his deep bows. "I was hoping you'd come back to us one of these nights."

"Were you indeed? I'm afraid I've come without company for once," she admitted, casting an idle glance around the dancers again. No spark of lavender. Vienna seemed so dark whenever Wolfgang was away.

"No matter!" Herr Stephanie said. "It's no matter! I've found someone I'd like you to meet!"

"You mean someone to meet Herr Conrad?" Constance asked cautiously.

"You'll see," he said with a wink. "Come on!"

Constance rose to her feet and followed Herr Stephanie around the edges of the room, swerving every so often to avoid dizzy dancers. In all the evenings she had come to the underground ball, Constance had never ventured so far from the exit. She wondered if any of the other dancers had noticed her. She wondered if she was still blending in. When Herr Stephanie mounted the staircase at the far end of the room, opened the door for her, and bowed as she passed through, she suddenly realized that the two of them might look rather like a pair of lovers slipping away from the crowd for a moment alone. For a tryst. An unwelcome memory of Wolfgang sneaking out of the ballroom with the man in black arose, but Constance pushed it away and buried it.

Beyond the ballroom was a grand vestibule, though the main doors of the house were boarded shut and black fabric had been nailed over the windows on the inside. A few lit candles had been left on dusty tables, their flames casting a dim glow that only offered hints at how magnificent this entryway had once been. Herr Stephanie had told her once that this house had belonged to a baron who had lost his fortune and fled the country rather than face his debtors, and that the underground ball had been the idea of a pair of footmen who had awakened one morning to find their master and his carriage missing.

If the front doors of the manor could have been thrown open, an arriving guest would have seen the doors leading to the sunken ballroom directly ahead and entrances to the wings of the house on either side. Above the ballroom was another grand doorway, with twin staircases winding along the walls and ending at either side of the main entrance. Constance craned her neck, trying to guess what the door at the landing led to, and made out the shape of an enormous chandelier hanging in the center of the room, framed by the staircases. She could hardly imagine what this house must have been like when the baron lived here, when parties had been accessed through this opulent vestibule instead of via a servant's corridor.

Herr Stephanie led her up one of the marble staircases, taking a candlestick with him to light their way. On the high walls above them, faded portraits of the baron's ancestors looked down at the intruders, their judgmental gazes obscured by a layer of cobwebs. Constance shivered, tugging Wolfgang's jacket tighter around her shoulders and jogging up the last few steps. From below, there was a surge of music as a couple emerged from the underground ball, warm golden light spilling across the marble floor when they opened the doors. Herr Stephanie paused, lifting his mask with his free hand and shooting a warning glance at Constance. She nodded and remained still until the lovers disappeared down one of the darkened wings of the house and the sound of their laughter faded.

When the room was silent again but for the muffled echo of the revelry downstairs, Herr Stephanie removed his mask, stepped up to the grand doors at the top of the double staircase, and knocked.

After a moment, Constance could hear someone shuffling around on the other side. She took another step toward Herr Stephanie, her imagination running wild. What sort of person might have taken refuge at the top of this staircase, and why did Herr Stephanie want her to meet him? She couldn't think of a single answer. Just as she was wondering if it would be unseemly of her to grip his arm for support, one of the enormous doors creaked open and a masked face appeared on the other side.

Herr Stephanie cleared his throat and whispered, "Herr... Clarence?"

The stranger raised an elegant hand and removed the mask, answering in a musical voice, "If no one else is here, Herr Stephanie, you might as well call me Clara."

Clara? There was another woman at the underground ball? Constance snatched her own mask away from her face, unable to stop staring.

It was true! In the flickering glow of Herr Stephanie's candle, she could just make out the angular features and sharp brown eyes of the person standing on the other side of the heavy door. Her dark hair was cut short and fell over her forehead in an unruly fringe; she was wearing an ill-fitting red jacket and a cravat, probably borrowed like Constance's. She grinned when their eyes met. "Herr Conrad, I presume," she said, pushing the door open wider. "So I'm not the only one with a husband that prefers being buggered to sleeping next to me after all."

"In fairness," Stephanie said, clearing his throat, "the majority of the guests here have wives at home. We just, ah, leave them... at home."

"Well, come in, both of you!" urged Clara. "Goodness knows I could use the company."

Herr Stephanie held the door, stepping back and holding the candle aloft for Constance as she hesitantly followed Clara inside. Once her back was turned, Constance was free to stare again. Their guide was a slender woman, even bordering on frail, but she held herself with as much confidence as the dancers in the ballroom beneath their feet. There was something about her that even reminded Constance of Wolfgang: her jawline, maybe, or her disheveled hair. Maybe it was just the aura of simmering enthusiasm that surrounded her.

Clara was leading her guests down a strange little passageway lined on one side with narrow doors, orderly numbers painted on each one in a faded shade of gold. Ahead of them, a door stood open, and flickering light from within illuminated a slice of the corridor.

"Excuse me? Herr- uh, Fraulein-?"

"Clara."

"Clara," Constance said, "Where- where are we, exactly?"

She glanced over her shoulder, her dark eyes dancing in the light from Herr Stephanie's candle. "The boxes! I used to play up here all the time when I was a child."

"When you were a child?" repeated Constance. "But... how long have you been coming here?"

Behind her, Herr Stephanie let out one of his nervous giggles. "She was born here!"

"Here? Was- was your father-?"

Clara stopped by the open door and grinned, leaning conspiratorially toward Constance. "My mother told me that my father was the old baron himself, but he was long gone by the time I had grown enough to look for a resemblance. And she was just a housemaid, after all." She gestured toward the door. "Welcome to my box!"

After glancing once more at Herr Stephanie, Constance stepped through the open door and into the low light beyond. She gasped at the view and sank into a chair. It was a box, just as Clara had said: a box overlooking a private theater! An old chandelier hung in the middle of the ceiling, laced with cobwebs which shone silver in the lamplight. It alone must have been the size of a carriage! Beyond it she could just make out the dim stage, its heavy, moth-eaten curtain riddled with stains. Similar boxes were lined across the walls, and she could see plush benches at the ground level, even with the entryway below. All this time, and the underground ball had been conducted each night beneath an abandoned theater! What other secrets must this old house be hiding?

Clara dropped into the chair at Constance's side, crossing her arms on the rail and leaning forward to rest her chin in the crook of her elbow. "I used to sit up here while mother worked, though I hardly remember what it looked like when anyone lived here. Now I just like to think what it would be like if all the candles in the chandelier were lit and the benches were filled with people."

"I've never been to a house with its own theater," Constance said reverently. "Could you even imagine living here?" When Clara cocked an eyebrow at her, she couldn't help smiling. "I mean, could you imagine being the master of this place? Having shows performed for your friends whenever you wished?"

"I'd be happy just to have a show performed at all," muttered Herr Stephanie.

"Poor Herr Gottlieb!" Clara crooned, turning to face the librettist. "I'm sure your opera would have been the highlight of the festival, if it hadn't been for those bastards stealing your idea."

Constance looked back at Herr Stephanie, who was wringing his hands and staring unhappily at the empty stage. "What bastards?"

"Frau Clara, I wouldn't call them bastards, especially not when speaking to-"

"Don't be so modest!" Clara interrupted. She raised her eyebrows at Constance, leaning forward as though she expected someone to overhear as she said, "The court librettist himself stole Herr Gottlieb's story and wrote his own libretto out of it, and now Maestros Salieri and Mozart are setting music to it anyway, knowing that it was stolen!"

Mozart? Constance gripped the rail tighter, leaning away. What was this woman talking about? A little gasp hissed between Stephanie's teeth at the sound of her husband's name, and he turned his wide-eyed stare on Constance.

"Well? Isn't that what happened?" insisted Clara, oblivious. "Mozart and Salieri-"

"More rumors!" Constance cried, throwing herself back in her seat with a huff. "Herr Stephanie, what's all this about? What did Wolfgang really do?"

"Look, this isn't really my business, not anymore, not really," Stephanie babbled. "Yes, it's true Da Ponte stole my idea, and then Salieri wouldn't listen, it's a shame, certainly, it's a shame after all the work I put into Gefährliche Liebschaften, but something else will come along." He nodded fervently, though the conviction didn't spread to his eyes. "I'll wait until after the festival, I suppose. Someone will buy it, somewhere. It's... it's an entertaining story."

"If you have a libretto, take it to Wolfgang's sister," Constance suggested. "She's staying with us at the Gods Eye and they need a plot for their opera."

"Who's Wolfgang?" asked Clara, earning another nervous titter from Herr Stephanie.

"My husband," Constance said coolly, "Wolfgang Mozart, the composer. He's one of the bastards you mentioned."

To Constance's surprise, Clara swore loudly. "You could have warned me!" she grumbled, shooting Herr Stephanie a dark look.

"But I tried!"

"Well that explains it, doesn't it? If her husband is a partygoer too, at least we know why he's working with the likes of Salieri."

"Frau Clara-"

"Wolfgang's out of town at the moment, actually," Constance corrected her. "That unfortunately pokes a hole in your slanderous little tale."

Clara sighed, leaning back in her seat and fixing a look of pity on Constance. "Is she new to this?" she asked Herr Stephanie.

"Frau Clara, if-"

"My husband isn't a liar," interjected Constance, the words coming out a little more loudly than she had intended. "He told me about this club, didn't he? He's the one who brought me here. So he trusts me! Why would he say he was in Salzburg if he was secretly right here in Vienna stealing librettos with Maestro Salieri?"

"It's just a rumor, just like you said!" Herr Stephanie blurted. His hands were clenched so tightly together that his knuckles were turning white. "A servant who works for Salieri thought he saw Wolfgang in his chambers, that's all! And with the way Salieri locks himself up when he's working on something, especially under pressure... but the man was probably mistaken! I never should have repeated it to anyone, only... only I was so angry about the libretto. I'm sorry, Frau Mozart!"

Constance took a long, slow breath, but still she felt indignation simmering in her blood as it coursed through her heart. Herr Stephanie had pretended to be such a good friend to her all these evenings since Wolfgang had first brought her to the club, and now! Now she knew the truth, that he had been spreading vile rumors about her husband just like everybody else. She took another breath and turned her stinging eyes toward the shadowy theater. Was there anybody left in this accursed city whom she could trust?

A pair of warm hands slid over hers, folding them together and patting them comfortingly. Constance rolled her eyes toward the ceiling and blinked until the hot tears began to dry, then faced Clara's sympathetic gaze.

"Frau Mozart?" Herr Stephanie ventured. "I really am sorry! I shouldn't have-"

Clara shushed him and squeezed Constance's hands. "Poor thing," she sighed. "You still love your husband very much, don't you?"

"Of course I do!"

"He must be very kind," Clara said gently. "But surely you understand the purpose of the party downstairs, don't you? Herr Gottlieb said you've been coming for weeks. You must have realized what your husband comes here to find."

Constance dropped her head, the image of their joined hands blurring. It felt so much worse to hear someone else say it. The thought of Wolfgang-earnest, kind Wolfgang-choosing to betray her, choosing to let someone else hold him, to let someone else's hands caress his skin, someone else's tongue into his mouth...! She couldn't bear it. She wouldn't stand for it.

As the roar in her ears began to recede, she realized Herr Stephanie was still talking. "Please, please accept my apologies, Frau Mozart! I never realized... I never meant to-"

"So you say Wolfgang and Maestro Salieri are together, writing an opera Herr Da Ponte stole from you?" Constance interrupted, her voice a little too sharp.

"It's merely a rumor based on-"

"Do you still have your version of the libretto?"

Herr Stephanie cleared his throat. "Well- yes, of course, but-"

"Bring it to the Gods Eye tomorrow evening," Constance said, dropping Clara's hands and rising from her seat. "Let Nannerl set it to music. I don't care if Wolfgang is involved or not; Aloysia and her friends need a libretto and you need a composer. If it's revenge you want on Maestro Salieri and Herr Da Ponte, this is your chance to mount an opera with the same story as theirs, but with music composed by a Mozart." She cast another glance at the dusty theater and nodded. "We can hold it here. Between Aloysia's friends and the deviants downstairs, we can bring in at least as big a crowd as Maestro Salieri's opera. Maybe bigger. That's what you want, isn't it?"

Herr Stephanie merely nodded, staring at her with awe in his eyes.

"She's brilliant!" Clara proclaimed with a wide grin. "We can certainly have this place cleaned up and ready before the emperor's festival begins!" She sprang to her feet and pressed a noisy kiss to Constance's cheek. "Such fire!"

Constance felt herself flush at the compliment, but she wasn't ready to let go of the rush of anger that had propelled her so far. The pieces had fallen together so easily, so obviously, and the result would be an opera that would both please her family and disgrace the man who had taken Wolfgang's career from him. The man who had taken Wolfgang from her. She looked down at the empty stage once more, then at the unemployed librettist with his name to avenge, and at the woman who knew the secrets of the house and its private theater. The woman with Wolfgang's jawline, with his smile, with his energy. With that same mischievous spark in her brown eyes.

There was something else Aloysia would do right now, Constance thought, cupping a hand under Clara's chin. She studied her upturned face for a moment, her long lashes, her pretty lips-but then she released her, letting her arm fall to her side. She couldn't, she couldn't betray Wolfgang like that. This could still be a misunderstanding. Instead, she caught her gaze and winked, saying, "You can come to the house tomorrow night, too. Our opera will need a manager."

Clara seized her hand and kissed it, then dropped into a low bow the way Herr Stephanie so often did. "At your service, Herr Conrad," she said. "I'd follow you anywhere."