Luce pivoted slightly in Daniel’s arms to face him.

“It’s just a hitch. Think about what we had to go through in Venice. But we got the halo. We’ll get the desiderata, too. That’s all that matters. When was the last time any of us were at this library, two hundred years ago? Of course things are going to change. It doesn’t mean we give up. We’ll just have to . . . just have to—” Everyone was looking at her. But Luce didn’t know what to do. She only knew that they couldn’t give up.

“The kid’s right,” Arriane said. “We don’t give up.

We—”

Arriane broke off when her wings began to rattle.

Then Annabelle yelped. Her body tossed in the air as her wings shuddered, too. Daniel’s hands shook against Luce as the foggy night sky morphed into that peculiar gray—the color of a rainstorm on the horizon—that Luce now recognized as the color of a timequake.

Lucifer.

She could almost hear the hiss of his voice, feel his breath against her neck.

Luce’s teeth chattered, but she felt it deeper, too, in her core, raw and turbulent, as if everything inside her were being wound up like a chain.

The buildings below shimmered. Lampposts doubled. The very atoms of the air seemed to fracture. Luce wondered what the quake was doing to the townspeople below, dreaming in their beds. Could they feel this? If not, she envied them.

She tried to call Daniel’s name but the sound of her voice was warped, as if she were underwater. She closed her eyes but that made her feel nauseated. She opened them and tried to focus on the solid white buildings, quaking in their foundations until they became abstract blurs of white.

Then Luce saw that one structure stayed still, as if it were invulnerable to the fluctuations of the cosmos. It was a small brown building, a house, in the center of the shuddering white street.

It hadn’t been there a second before. It appeared as though through a waterfall and was visible only for a moment, before it doubled and shimmered and disappeared back into the expansive row of modern, monochrome townhouses.

But for a moment, the house had been there, one fixed thing in all-consuming chaos, both apart from and a part of the Viennese street.

The timequake shuddered to a stop and the world around Luce and the angels stilled. It was never quieter than in those moments right after a quake in time.

“Did you see that?” Roland shouted, gleeful.

Annabelle shook out her wings, smoothing the tips with her fingers. “I’m still recovering from that latest violation. I hate those things.”

“Me too.” Luce shuddered. “I saw something, Roland. A brown house. Was that it? The Foundation Library?”

“Yes.” Daniel flew in a tight circle over the place where Luce had seen the house, zeroing in.

“Maybe those booty-quakes are good for something,” Arriane said.

“Where did the house go?” Luce asked.

“It’s still there. It’s just not here,” Daniel said.

“I’ve heard legends about these things.” Roland ran fingers through his thick gold-black dreads. “But I never really thought they were possible.”

“What things?” Luce squinted to try to see the brown building again. But the row of modern townhouses stayed put. The only movement on the street was bare tree branches leaning in the wind.

“It’s called a Patina,” Daniel said. “It’s a way of bending reality around a unit of time and space—”

“It’s a rearrangement of reality in order to secret something away,” Roland added, flying to Daniel’s side and peering down as if he could still see the house.

“So while this street exists in a continuous line through one reality”—Annabelle waved at the townhouses—“beneath it lays another, independent realm, where this road leads to our Foundation Library.”

“Patinas are the boundary between realities,” Arriane said, thumbs tucked into her overall suspenders. “A laser light show only special folks can see.”

“You guys seem to know a lot about these things,” Luce said.

“Yeah,” Arriane scoffed, looking as if she’d like to kick another cloud. “’Cept how to get through one.”

Daniel nodded. “Very few entities are powerful enough to create Patinas, and those that can guard them closely. The library is here. But Arriane’s right. We’ll need to figure out the way in.”

“I heard you need an Announcer to get through one,” Arriane said.

“Cosmic legend.” Annabelle shook her head. “Every Patina is different. Access is entirely up to the creator.

They program the code.”

“I once heard Cam tell a story at a party about how he accessed a Patina,” Roland said. “Or was that a story about a party that he threw in a Patina?”

“Luce!” Daniel said suddenly, making all of them startle in midair. “It’s you. It was always you.” Luce shrugged. “Always me what?”

“You’re the one who always rang the bell. You’re the one who had entry to the library. You just need to ring the bell.”

Luce looked at the empty street, the fog tinting everything around them brown. “What are you talking about? What bell?”

“Close your eyes,” Daniel said. “Remember it. Pass into the past and find the bellpull—”

Luce was already there, back at the library the last time she’d been in Vienna with Daniel. Her feet were firmly on the ground. It was raining and her hair splayed all across her face. Her crimson hair ribbons were soaked, but she didn’t care. She was looking for something.

There was a short path up the courtyard, then a dark alcove outside the library. It had been cold outside, and a fire blazed within. There, in the musty corner near the door, was a woven cord embroidered with white peonies hanging from a substantial silver bell.

She reached into the air and pulled.

The angels gasped. Luce opened her eyes.

There, in the center of the north side of the street, the row of contemporary townhouses was interrupted at its midpoint by a single small brown house. A curl of smoke rose from its chimney. The only light—aside from the angels’ wings—was the dim yellow glow of a lamp on the sill of the house’s front window.

The angels landed softly on the empty street and Daniel’s grip around Luce softened. He kissed her hand.

“You remembered. Well done.”

The brown house was only one story high, and the surrounding townhouses had three levels, so you could see behind the house to parallel streets, more modern white stone townhouses. The house was an anomaly: Luce studied its thatched roof, the gabled gate at the edge of a weed-ridden lawn, the arched wooden asym-metrical front door, all of which made the house look as if it belonged in the Middle Ages.

Luce took a step toward the house and found herself on a sidewalk. Her eyes fell on the large bronze placard pressed into the packed-mud walls. It was a historical marker, which read in big carved letters THE FOUNDATION

LIBRARY, EXT. 1233.

Luce looked around at the otherwise mundane street.

There were recycling bins filled with plastic water bottles, tiny European cars parallel parked so closely that their bumpers were touching, shallow potholes in the road. “So we’re on a real street in Vienna—”

“Exactly,” Daniel said. “If it were daytime, you would see the neighbors, but they wouldn’t see you.”

“Are Patinas common?” Luce asked. “Was there one over the cabin I slept in on the island back in Georgia?”

“They are highly uncommon. Precious, really.” Daniel shook his head. “That cabin was just the most se-cluded safe haven we could find on such short notice.”

“A poor man’s Patina,” Arriane said.

“I.e., Mr. Cole’s summerhouse,” Roland added. Mr. Cole was a teacher at Sword & Cross. He was mortal, but he’d been a friend to the angels since they’d arrived at the school, and was covering for Luce now that she’d left. It was thanks to Mr. Cole that her parents weren’t more worried than usual about her.

“How are they made?” Luce asked.

Daniel shook his head. “No one knows that except the Patina’s artist. And there are very few of those. You remember my friend Dr. Otto?”

She nodded. The doctor’s name had been on the tip of her tongue.

“He lived here for several hundred years—and even he didn’t know how this Patina got here.” Daniel studied the building. “I don’t know who the librarian is now.”

“Let’s go,” Roland said. “If the desideratum is here, we need to find it and get out of Vienna before the Scale regroup and track us down.”

He slid open the latch on the gate and held it aside for the others to pass. The pebble path leading to the brown house was overgrown with wild purple freesia and tangled white orchids filling the air with their sweet scent.

The group reached the heavy wooden door with its arched top and flat iron knocker, and Luce grabbed Daniel’s hand. Annabelle rapped on the door.

No answer.

Then Luce looked up and saw a bellpull, woven with the same stitches as the one she’d rung in the air. She glanced at Daniel. He nodded.

She pulled and the door creaked slowly open, as if the house itself had been expecting them. They peered into a candlelit hallway so long Luce couldn’t see where it ended. The interior was far bigger than its exterior suggested; its ceilings were low and curved, like a rail-road tunnel through a mountain. Everything was made of a lovely soft-pink brick.

The other angels deferred to Daniel and Luce, the only two who had been there before. Daniel crossed the threshold into the hallway first, holding Luce’s hand.

“Hello?” he called out.

Candlelight flickered on the bricks as the other angels entered and Roland shut the door behind them. As they walked, Luce was conscious of how quiet the hallway was, of the echoing thumps their shoes made on the smooth stone floor.

She paused at the first open doorway on the left side of the hall as a memory flooded her mind. “Here,” she said, pointing inside the room. It was dark but for the yellow glow of a lamp on the windowsill, the same light they’d seen from the outside of the house. “Wasn’t this Dr. Otto’s office?”

It was too dark to see clearly, but Luce remembered a fire blazing cheerily in a hearth on the far side of the room. In her memory the fireplace had been bordered by a dozen bookshelves crammed with the leather spines of Dr. Otto’s library. Hadn’t her past self propped her wool-stockinged feet on the footrest near the fire and read Book IV of Gulliver’s Travels? And hadn’t the doctor’s freely flowing cider made the whole room smell like apples, cloves, and cinnamon?

“You’re right.” Daniel took a glowing candelabra from its brick alcove in the hallway and held it inside to give the room more light. But the grate over the fireplace was shut, as was the antique wooden secretary in the corner, and even in the warm candlelight, the air seemed cold and stale. The shelves were sagging and distressed by the weight of the books, which were covered with a mist of dust. The window, which had once looked out on a busy residential street, had its dark green shades drawn, giving the room a bleak sense of abandonment.