JULIAN HAD ONCE SAID SOMETHING to him that struck Nicholas now, as he breathed in the fog and cold mist: All cities are jealous of Paris, but Prague is the envy of Paris.

Tucked into the alcove of the building where the passage had released them, he had only been able to see the busy market in the open courtyard before him. As the weather turned and night crept in, the stalls rapidly emptied. Footsteps and cart wheels clattered over the cobblestones as all manner of people, in all manner of simple, colorful dress, fled the rain, carried off by surprised laughter and shouts.

Though he’d hoped his breeches and shirtsleeves would be unremarkable enough for him to pass among the century’s occupants unnoticed, Nicholas was rather dismayed to find that it was not the case, unless he wanted to commit to the part of a peasant and rend his clothing. The men of this time wore doublets and jerkins, in the sort of style that made them appear to be strutting around with their chests puffed out like pigeons. Or, in the case of the paler fabrics, enormous eggs with limbs.

He turned to Sophia, only to find that she had shed her jacket, pulled the shirt out of the waist of her breeches, and affixed her belt over both, in a close approximation of a tunic. Perhaps not exactly correct, but perhaps not quite so incorrect, either. At least they’d both managed to keep their hose from ripping. Whatever small consolation that was.

Although he felt less aware of the color of his skin than he had in the eras they had passed through to arrive here, Nicholas now was struck by the first stirrings of doubt that the residents of the city might explain his presence away as a Moor or Turkish merchant. It was a blessing, then, to have the soaked, darkened city streets to themselves for a short time, and he meant to make the most of it.

Of course, that was before he stepped out from under their shelter and truly took stock of the place.

He understood what Julian had meant now. Rather than charge forward, Nicholas’s feet came to a sudden, halting rebellion. Rain ran down his face in rivulets, soaking him as he studied the twin spires of a Gothic church. Around him, the sweet faces of the buildings stretched up into the low-slung clouds, the precise curves and angles of the gables and finials glowing in the odd light. At first look, it had all seemed rather simplistic in design, but he was almost delighted to find that the city defied him, that it refused to be absorbed in a single glance. The roads and paths away from the market curved into shadows, inviting mysteries. There was an unreal quality to the place, one that made it seem as though it had been someone’s dream, imagined into stone and timber.

Sophia smacked the back of his head, knocking him out of his reverie.

“‘We must make haste! We cannot delay!’” she said, in a mocking version of his voice. “So let’s stand around and gawk where anyone can see us!”

Despite having sworn to himself that he wouldn’t keep rising to her taunts, Nicholas felt himself bristle. “I was—”

“Good evening, sweet lady and kind sir.”

Nicholas spun around, searching through the sheets of rain for the source of the small voice. A young blond boy dressed in a gold-and-ivory doublet and jerkin, his hose dampened by mud and rain, stood a few feet away, glowering at them. The feather on his jaunty little cap was wilted, and flopped as he tilted his head. “My mistress has invited you to take tea with her.”

A hot cup of tea sounded like heaven itself, actually. But Sophia answered before Nicholas could accept. “We take wine, not tea.”

He could have argued against that, very strongly, but the boy pouted in response and executed a smart little bow. Sophia smirked at Nicholas, just as he’d begun to suspect he’d missed something—some sort of code.

“If you and your…guest…would please follow me?”

Their golden child led them around the tower the passage had emptied into, and Nicholas was arrested by the sight of a large clock on its side layered with symbols, arms, charts. At first glance, the intricate layers of its face reminded him of nothing so much as the astrolabe.

Sophia retraced her steps back to him, her eye squinting at it. “Will you please take that ridiculous look off your face? It’s an astronomical clock.”

Which told him nothing other than that this, perhaps, was like a great geared astrolabe that also served the useful function of telling time, rather than corrupting it.

The boy continued on through the streets of Prague with the ease of a native, ignoring the architecture, the art embedded in the city’s skin. Behind him, Nicholas was so absorbed in the wonders of the city that it took him longer than it might have otherwise to notice the peculiar thing unfolding around him.

He slowed his pace, wondering if it was his eyes, or…Nicholas was exhausted, practically dragging himself forward. But, still, he’d felt the sting of invisibility and dismissal far too many times to let this stand.

The next small cluster of men and women approached quickly, giving him another opportunity to investigate. But—again. He sucked in a breath, watching as the soldiers, the young woman, an elderly man, all stopped despite the rain, and turned their backs as he, Sophia, and the boy passed them.

“What are you huffing and puffing about?” Sophia asked. “You sound like a teakettle about to go off.”

“We’re being shunned,” he said in a low voice, so the child wouldn’t hear. “Or at least, our guide is.”

Sophia’s bewildered expression turned to one of muted surprise when he pointed it out to her, splashing through the puddles of the next narrow street. What confused him, truthfully, was that, despite their firm action, these people bore no signs of disgust, or even scorn. No obvious markers, such as sneers, or hateful, distrusting eyes. In fact, their expressions were as serene as marble statues, and once their party had passed, the men and women would turn back around and continue on their way. It made his skin prickle and tighten around his bones.

The boy glanced over his shoulder and must have caught his expression, for he said, “Don’t be troubled, sir. They cannot help it.”

Which meant…what, precisely? They were somehow being compelled? And in such perfect uniformity?

“Oh, I’d forgotten about this,” Sophia said, waving away his attempts to engage her on this. “Some trickery to ensure there are no real witnesses. Grandfather—Ironwood—believes the Belladonna loaded everyone in this city with so much gold they don’t dare breathe her name, let alone acknowledge her or her guests.”

While money could buy a great deal, no matter the century, this seemed a step beyond mere coordinated cooperation. Nicholas crossed the short distance between himself and the nearest woman. She looked to be a servant, perhaps, as she was older and wore unadorned clothing. On closer inspection, the basket over her arm carried a small heap of vegetables, covered with a piece of burlap. She went impossibly still as Nicholas stepped closer to study her impassive face, and risked a faint tap between her shoulder blades.

The woman did not move, except to breathe. Not so much as a blink.

“You said she was not a witch,” Nicholas whispered as he caught up to Sophia and the boy again. “You swore it!”

“She isn’t,” Sophia insisted, glancing back over her shoulder just as the woman shook herself, as if coming out of a deep sleep, and turned to continue on her way. Nicholas did not miss the rare flicker of uncertainty on her face as she admitted, “At least…I am reasonably certain she is not.”

THE BOY BROUGHT THEM AT LAST TO A STREET OF STORIED MANSIONS. Perhaps “small palaces” was a more apt description, each marrying different shades of colors and styles of stonemasonry. The homes announced themselves to passersby with doors that looked as though they could withstand battering rams if necessary, and windows from which candlelight and the gazes of servants fell softly over the three of them.

At the very end of the street, past the splendor of Prague’s wealthy, lived a narrow little shop, which leaned so severely to the right on its haunches that the windows and door had been installed on a slant. Its front window was covered with a curtain, blocking the interior, and it bore no sign.

Nicholas reached up to touch Etta’s earring on its leather cord and took a steadying breath. As he followed Sophia inside, the shop coughed up warm dust and the smell of rotting earth. Dozens of candles were scattered around the room like guiding stars. The dingy light, however, only served to make the shelves of bottles and jars, many cracked and half-full, seem filthier than the lace of spiderwebs connecting them.

Half of these same shelves had buckled and snapped, spilling their contents onto the floor, where they had been promptly forgotten. Wax from the candles was dripping onto the glass cases and chairs, many of which were torn or broken altogether. As much as he had longed to be in a place warm enough to begin drying out his clothes and thawing his blood, Nicholas’s skin only felt an overwhelming itchiness amid the decay.

“Madam!” the boy called.

A crimson curtain behind the far counter rustled, and out from under the portrait of a doll-faced child came a young woman. Her hair was like a raven’s wing: black, with a natural sheen that caught the candlelight, even without the gold-and-pearl netting that had been pinned to it. A heavy gold cross hung around her neck, dipping into the low bodice of her strawberry-pink silk gown—at odds with the filth that seemed to be steaming around her. Her face, with its too-large eyes and lips, was oddly arresting, so much so that Nicholas took a step toward her without meaning to. The thoughts that had been trying to sort themselves out went soft at the edges.

The woman received the boy warmly, leaning down to ghost a finger along the bridge of his nose, her smile as sweet as pure honey. He nodded at something she whispered in his ear and happily skipped off to a stool a short distance away, reclaiming a thin leather volume.

The woman glimmered in the candlelight as she smiled at them. Her skin, the gold, the beading and metallic thread shot through her gown—all called to him, shining and bold. The light caught her like flame on glass.

Nicholas leaned back against the pull of her, cocking his head to the side to better study her. There was something in the way she didn’t move so much as flicker around, like the candles burning on the counter near her hands—something that made him question his eyes.

“See?” Sophia scoffed. “I told you you’d forget Linden soon enough.”

He whirled on her, grasping for the words that only a moment before had been poised on the tip of his tongue. It wasn’t that. Nicholas didn’t feel a rush of attraction that set him back on his heels, the way he had with Etta, but…this was…it seemed closer to the flush that came with too much whiskey on a too-empty stomach. A sickness.

“Welcome,” the woman said, in such a soft voice that Nicholas and Sophia took another step forward to hear her. The candles mimicked their movement, and, for just a moment, he was able to tear his eyes off the woman—the Belladonna—and notice that, in the middle of the stack of reeking, swollen tallow candles was one burning a sullen blood red.

“Welcome, weary travelers,” she said again, this time with a smile that revealed beautifully white teeth, like seed pearls—something unheard-of for anyone in this era. “How may I assist you?”

This woman? This was the woman who had dueled with Cyrus Ironwood and won her independence from him? Perhaps this…beguiling charm…worked even on the stone-hearted.

“We’ve come to trade for information,” Sophia said, leaning an arm and hip against the counter.

Nicholas glanced up at the slight vault of the ceiling, not quite a dome. Much of it was covered with a damp cloak of dust and mildew, browned by time, but here and there he could make out the strange, mystical symbols that bordered its edges. At the peak was a large silver crescent moon, half masked by the dark clouds painted around it.

“I possess many remarkable objects,” the woman hedged. “And know of many more.”

“Can we cut through this nonsense and get to the heart of this?” Sophia said. “I was made to believe that you know everything and everyone. If that isn’t the case, we’ll take our business somewhere else.”

“Perhaps if you were to be more specific about what it is you’re searching for?” The Belladonna’s voice sounded as though it were being coaxed out of a violin.

“We’re looking for information pertaining to, ah,” Nicholas said, “travelers of a particular nature.”

“Perhaps you could be a little less specific and a bit more cagey,” Sophia muttered, shaking her head. “I’d love to be here to greet the next century.”

A sound shuddered up from beneath the floorboards—a heaving, stomping sound that seemed to rattle even the timber beams overhead. A portrait of a benign, pale man tumbled from the nearby wall behind where the boy sat. It smashed out of its frame when its gilded corner struck the ground. The steps passed beneath them—Sophia straightened, tracking the sound with her eye. Nicholas kept a hand on the knife at his side.

“Who the devil is that?” he asked.

The woman smiled serenely. “I sell the finest of elixirs, sir. Perhaps I might interest you in a set for your pretty little wife at home?”

“That’s not what he asked, you stupid cow—”

Sophia’s words were cut short by the tremendous bang of the door behind her as it struck the wall, and the sudden appearance of a bundle of black-and-silver silk and netting. All of which didn’t appear, so much as roll toward them with the force and menace of a thundercloud.

A woman nearly as tall as Nicholas strode forward. The bottom half of her face was hidden beneath a veil of black lace, but her eyes were a gleaming, almost feline yellow. Somehow, either by piercing or some art, three small pearls trailed down from the corner of each eye like tears. Her décolletage was modestly covered by a sheer panel of white fabric, but what Nicholas initially took for lace was anything but. The markings were the climbing, swirling lines of what appeared to be a tattoo. When she spun toward Sophia, Nicholas saw that her snow-white hair had been braided, intricately looped and knotted together.

“Who—?” The woman leaned toward Sophia, sniffing the air around her.

Sophia let out a small cry of surprise, swatting at her, but the woman had already moved on. Nicholas leaped back instinctively as she swung her attention toward him, subjecting him to the same sniffing. Truly, she sounded like a pig searching out a truffle, her teeth clattering behind the veil. He was dosed with her scent—that earthy undertone he had detected when they’d first entered the shop.

“Ma’am,” he began, with as much composure as he could gather, “if you would be so good as to—”

She spun, carrying the same hint of damp soil and lavender away with her.

“Sir, please let me show you our latest arrivals,” the woman behind the counter said, her smile never once faltering. The other woman glanced back, first at her, then the boy.

“Put her out.” If the first woman sang her words, this one crushed them between her teeth.

The golden boy marked his place in his book and went over to the counter. He planted two hands on its dusty surface and jumped up, just high enough to blow out the bloodred candle Nicholas had noted before.

The Belladonna vanished, disappearing into the candle smoke that trailed up toward the groaning rafters.

That settled, the boy returned to his stool, picked up his book, and resumed his place in the story.

Sophia jumped forward, a wild expression on her face as she looked behind the counter for the woman—she met Nicholas’s gaze when she looked up again and shook her head.

Disappeared. Gone.

Impossible.

He might have to accept that they were edging toward the shadows of the unnatural. Nicholas knew he would need to be on guard, and despite his shaky faith in a higher power, found himself thinking those words he’d heard Captain Hall say throughout his childhood: God defend us.

“How…? Are…?” Nicholas was not quite sure what he meant to ask.

The woman in black stormed back toward Sophia, who lifted a leather-bound volume off the floor and sent it flying toward the older woman’s head, coming within inches of striking her.

The sniffing intensified, until finally the woman held out an arm, silvery black lace dripping from the end of the sleeve. “Come here to me, beastie.”

Sophia took a rather large step back.

Before Nicholas could leap forward, the woman snatched Sophia by the arm and whirled her around, as if to swat her bottom. In one smooth movement, the woman pulled up the back of Sophia’s shirt and pulled something out that had been tucked into the belt around the girl’s waist.

For a moment Nicholas thought it might have been another trick of his eyes, because when her hand emerged it was holding a long, thin blade, but the end of it had been snapped off, leaving it a jagged claw. The base was adorned with a large ring, thin bands of silver weaving in and out of each other.

“Good God!” The words burst out of him as the woman held the pointed end up to her nose with one last, satisfied sniff. “You’ve been carrying that around this whole time?” he asked Sophia. “Where did you come across such a thing?”

Even as the words left his mouth, he knew. The body of the Linden guardian in Nassau, the one with the peculiarly small wound through his ear. She had reached the body first, and had somehow taken up the blade in the darkness of night. Without him ever noticing.

And she had held on to it for…what purpose, exactly? His guts clenched, picturing her expression of joy as she drove it through him while he slept.

Sophia refused to look in his direction. “How did you know I had it?”

The question was directed to the other woman—the true Belladonna, Nicholas suspected.

“The blood smells like the rotting intestines of a goat,” the woman growled at her. “This will be payment enough for entry.”

Holding it up to the candlelight, she studied something on the ring that Nicholas couldn’t quite make out—it might have been the etching of a sun. Her breath made the veil over her mouth flutter.

“Payment?” Nicholas heard the disbelief in his voice.

“Yes, beastie. Payment. This is a place of business. Or did you expect me to offer you refreshments and the moon?”

“Is information part of the deal?” Sophia asked, eyeing her with her usual look of mistrust.

“It depends, of course, on what it is you wish to purchase,” the Belladonna said. “I have been known to barter. From time to time. Boy, lock up the shop.”

“Yes, madam,” the boy said, brave enough to give her a petulant look for interrupting his reading again, but not brave enough to ignore the order.

“Children,” the Belladonna huffed as she led Nicholas and Sophia to the door behind the counter. “The only thing they’re good for is eating.”

Sophia barked out a surprised laugh, but Nicholas wasn’t quite convinced she was joking, given the casual way the woman had begun to twirl the blade with a shocking disregard for her fingers.

“She can follow me,” the Belladonna said, gesturing to Sophia as she began down the dark stairs, “and to hell with you, you humorless sop. Oh—you’ll want to hold your breath as you take the last few steps. If you faint, you roll down at your own peril.”

“I beg your pardon?” Nicholas caught a hint of something vaguely putrid and found himself doing as asked.

The lower level seemed to be two flights down, lit only by the faint orange haze crawling up the steps from fires below. Nicholas had a vague memory of something Julian had told him—that there was a kind of underground city in parts of Prague where they’d been forced to build the streets and buildings up to avoid flooding. The overall impression he had was of climbing through a dark vein to reach the city’s pale bones.

The light was coming from a fire in the corner of what looked to be some sort of workshop. The first small section they moved through contained mostly plants and herbs left to dry, as well as what looked to Nicholas like an area for blowing glass. They continued down the narrow, rough stone artery that connected that room to the next. At the very center of the room was a sort of circular stove, each layer stacked upon the next like the tiers of a dingy stone cake. Glass bottles ringed it like ornaments, many with long, hollow stems for pouring the liquids inside into another, simpler bottle below. As she passed by it, the Belladonna stooped to fan the small fire burning inside its base. Once past it, they were confronted with the sight of what looked to be a bell-shaped oven with small openings, as well as barrels, and mice scampering around them.

“Are you an alchemist?” Sophia asked, understanding the odd sight.

“Well spotted,” the Belladonna deadpanned. “I dabble. You might consider the use of my youth elixir, beastie. You look old beyond your age.”

Nicholas grabbed Sophia’s shoulder before she could make good on the murder in her expression.

One last jaunt down another hall brought them to their destination: an even smaller, darker room. Its only occupant, save for them, was a painting that stood taller than himself, and wide enough to cover the entirety of the wall. Nicholas’s eye was caught first by the glowing moon depicted in the dark, cloudy sky, and next, by the waves washing up onto a deserted, unknown shore.

“Now,” the Belladonna said, “do not touch anything, do not look into any of the mirrors, do not sit on my chairs, and most of all, know that thieves will be dealt with in the manner of ancient justice.”

Sophia gave a sarcastic salute, but Nicholas put a hand on the knife at his side.

With no further instructions or warnings, the Belladonna turned and stepped inside the painting.