The lobby was straight from another era, as Mrs. Sharpe had said it would be. Arched columns and old lamps, an expanse of polished stone on walls and underfoot, even an old post box; countless undisturbed details gleamed in a dim interior light.

On the wall above the second set of front doors was a boldly lettered statement:

ALL PASSES — ART ALONE ENDURES.

“Where to, ma’am?” asked the one elevator operator in sight. He held back an intricate metal gate as Mrs. Sharpe stepped inside, obviously pleased that all was looking and sounding as it should.

“The top,” Mrs. Sharpe replied. “Tenth floor. Everyone should start there.” The elevator wasn’t much more than a closet, and only five of them fit comfortably inside.

“I’m the only operator at this time of day,” the man apologized. “Not like old times.”

Ms. Hussey stayed downstairs with Petra and Tommy. “Meet you up there,” she called cheerfully.

As the gate latched, they heard Mrs. Sharpe saying, “Cast bronze elevator doors on every floor, such style. They will surely outlive —” The door clicked shut, ending her sentence.

“Ms. Hussey,” Petra said slowly to her old teacher. “Would you say it’s a good or bad sign if we keep noticing echoes? Things that are coincidences but not quite, because they feel less random — like, well, they’ve happened because of something else?”

The young woman frowned, studying Petra’s face. “Good or bad? Well, I guess when I notice a human pattern it usually seems as though it’s connected to something I want to know.”

Tommy, looking up at the statement ART ALONE ENDURES on the wall, suddenly felt as if someone had flashed a camera in his face. FIND ARTS FINE ARTS … FIND ARTS FINE ARTS 6 …

“Scinigaz!” he shouted. As he turned happily first to Petra and then to Ms. Hussey, he opened his mouth to speak and then snapped it shut again.

Someone had stepped through the front doors behind Ms. Hussey, and that person had the soft, wary tread of a large cat.

Ms. Hussey jumped when she heard the words, “Well, if this isn’t a popular spot today!”

“You stay right here,” she ordered Tommy and Petra. Grabbing Eagle’s arm, she turned him before he and the two kids had even said hello. The adults walked several steps away.

Eagle glanced over Ms. Hussey’s shoulder at the kids and winked. Looking down at Ms. Hussey, he shrugged and spread his hands, as if to say, Not my fault.

“I’ve got something to tell you, something big,” Tommy whispered to Petra. She shifted her gaze from the two adults to her friend. “I’m so glad you didn’t let me quit this morning!”

“What?” she asked, but before Tommy could say another word, Ms. Hussey was back at their side and Eagle was gone.

“Where’d he go?” Petra asked, looking around. “That was a fast visit!”

“Cinigarinigefinigul,” Tommy whispered.

Ms. Hussey raised her eyebrows but didn’t ask. She wasn’t, after all, in a position to, having just said something to Eagle that she didn’t want the kids to hear.

*  *  *

The elevator ride up to the top of the Fine Arts Building was silent. The floors shot by, one after the other, as Tommy thought impatiently, All passes, all passes …

Petra was busy wondering what both Tommy and Ms. Hussey knew, Ms. Hussey was busy wondering about what a number of other people knew, and Tommy wondered what to do — or not to do.

*  *  *

“Ms. Hussey! Hurry!”

Halfway down the hall, the other kids clustered around a wooden bench, and on the bench, Mrs. Sharpe leaned against Gam, who fanned her with a handful of gallery invitations.

“Just a spell,” Mrs. Sharpe muttered as Ms. Hussey ran over. “Little fresh air … You two bring me down, and we’ll wait for the kids in the limo. I want them to see … while here …”

“Oh, dear,” Ms. Hussey said. “I just saw Eagle and sent him away. Let’s try to get her to her feet,” she said to Gam, who handed her large purse to Zoomy, freeing both hands.

Soon the three adults were headed downstairs in the elevator. As the gate closed, Ms. Hussey called out, “Twenty minutes tops! You can walk down the ten stories and see the building that way. And keep your phones on.”

“Hold on to that bag and don’t forget that all raisins are really grapes,” called Gam as the doors closed.

“What does that mean?” Tommy asked.

“Just that old people are as smart as young ones.” Zoomy was looking dubiously at the purse. “She always says that when she wants me to behave and not do something dangerous.” He clicked the pocketbook open. “Oh, a Baggie of dillies.”

As Zoomy opened it, Calder groaned. “I’m still too full of cake and pie, aren’t you?”

“For good luck,” Zoomy said in such a firm voice that the other four obediently took a small bite from the one bean he passed around. “Hodilly-hum,” he said, closing the purse and tucking it under one arm. “Come on.”

“Wait, guys.” Tommy then spilled his “FIND ARTS FINE ARTS 6” flash, and the others responded with a satisfying buzz of ideas and questions. Both Petra and Early patted him on the back — a definite first — and he blushed happily.

In the next half minute, the group agreed on several things: One, they had almost no time to disagree. Two, they needed to get to the sixth floor but also do a quick survey of the other seven, not counting the first floor, which was mostly lobby. Three, if there was a manager’s office for all these studios, they needed to get inside it, and fast. Separating — with phones in pockets — was the only option.

Zoomy and Tommy headed for the sixth floor. They would explore and listen at each of the doors. Calder, Petra, and Early would split up and cover the other floors, reading signs outside the studios and hunting for the main office. Feet thumped off in all directions.

Petra, exploring the top floors, found signs outside Frank Lloyd Wright’s old studio and Lorado Taft’s. She also paused for a moment to admire some huge paintings that looked like the wall murals Mrs. Sharpe had mentioned: Ladies in long, flowing dresses danced through flowery landscapes and around admiring men. She thought of the mysterious party sounds they’d heard at the Farmer, and wondered what this building sounded like when empty at night. Maybe art and ghosts went together.

Calder and Early passed rooms with signs for printmakers, painters, architects, sculptors, and jewelers. Each heard singing from behind a number of doors, and sounds of violin, guitar, and piano lessons. A few doors had no identification on the outside. There were benches in most of the halls and small tables covered with takeaway cards and brochures.

Zoomy and Tommy had found three unmarked doors on the sixth floor. Of the marked doors, some belonged to pianists, who were making a wonderful amount of noise. Others belonged to small arts organizations whose names the boys didn’t recognize.

It was Calder who stumbled on the Fine Arts Management office, a wooden door in the middle of the third floor hallway. He turned the knob and stepped inside.

“Yes?” asked someone who looked like an artist, a student, or both. Calder’s mouth fell open, studying this young woman’s face tattoos and spiky blue hair. Was that a cat playing a fiddle on one cheek and a dish and spoon holding hands on the other?

“Oh!” Calder said, wishing he’d called one of the girls to help. “Ah, I’m interested in recent studio rentals. Like, within the last month.”

“You’re looking for someone specific?”

“Their sign must not be up yet and I’m not sure what name they used.” Calder blundered on. “Could I see the list of recent renters?”

“Doesn’t sound like something I should do, does it?” The girl smiled, which made the dish lean toward the spoon. “But if you give me a hint …”

As Calder stirred his pentominoes, the girl peered over the edge of the counter to see what he was doing. “Sorry, just a math tool I carry,” he blurted. “Great for thinking. And, oh, this person said they’re on the sixth floor.”

The girl turned toward her computer and scrolled through some names. “Not too much lately. Any idea what size studio space or what they wanted it for?”

“Not too large. Good temperature controls. For storage and, ah, work on some largish art pieces.” The computer was, frustratingly, turned at an angle that he couldn’t quite see. Calder’s pentominoes clacked some more.

“What are those?” the young woman asked. “I like math games. I use them in my art.”

Calder spilled his pentominoes onto the counter with a full-arm flourish that he hoped would knock the computer screen in his direction. It did. “Oops, I’m so clumsy!”

In the confusion that followed, the girl picked several of the pieces off the floor and Calder read the screen as fast as he possibly could. There was only one recent rental, and it had been made the week before the theft, in early March:

SALLY STAYZ, 619

“Here, you can keep these, a present,” Calder said before rushing back out the door. Maybe this would distract her from realizing she’d just handed him a giant clue. Minutes later, the five were gathered outside 619, which had no sign and was quiet inside.

Calder was bright with excitement. “It’s here. I know it!” It was like being on that Rembrandt shipwreck and seeing help on the way — he could practically taste the rescue.

“Lucky you found that room number after I put the big picture together,” Tommy reminded him.

“And after I realized there might be something special about the Fine Arts Building.” Early smiled.

Tommy turned her way, suddenly remembering the girl sitting frozen in Mrs. Sharpe’s living room, the one with the flying cookies on her lap. One of the best things about friends, he thought to himself, is that you stay around each other long enough to get cooler — and to live through the lemme-outta-here, uncool moments.

“Scaz.” He grinned at her.

“Shhh, you’ve all done great work, but keep your voices down! These are open stairwells and anyone can hear us.” Petra tapped her watch. “We’re down to five minutes.”

Tommy turned the door handle. It was locked.

“Wait, listen,” Zoomy hissed to the group, his ear against the door. “I just heard a beep from inside there, like a cell phone sound.”

“Whoa,” muttered Tommy. “I wish we knew how to pick locks.”

“The person you talked with, Calder — she must have a master key to all the studios,” Zoomy pointed out. “For fire and stuff, you know?”

“She’s not gonna just give it to us!” Calder protested.

“We could call Eagle,” Early volunteered. “I’ll bet he could figure out how to pick that lock. He’s probably good at criminal stuff. And what if we can’t get back here ourselves? We’re all grounded right now. But do we trust him to come back here without us?”

“Not exactly.” Petra was frowning. “Tommy and I saw him come into the building just now, as if he didn’t know he’d find us. Ms. Hussey sort of steered him away. Then he left without saying good-bye. In fact, she kept us apart.”

“And guess what?” Calder added. “I forgot to give Tattoo Cheeks the T pentomino, it’s still in my pocket. T for turn. It’s a sign that we have to return!”

Hurrying back to the office, the group concocted a drama that they hoped would get them into the studio.

As their voices spiraled down a couple of stories, a young man in a black jacket peered out of a doorway on the sixth floor. Glancing in both directions, he spoke quietly into a phone, one trembly hand cupped over his mouth.

*  *  *

Inspired by Mrs. Sharpe’s spells during the past couple of days, the five piled into the office and Petra flopped down on the floor in what she hoped looked like a faint.

“Now we really need help,” Calder said, trying to sound panicky. “And here’s the T,” he added, dropping it on the counter. “T for trust.”

“Goodness!” The girl shot him an odd glance but jumped to her feet. “Want some water? There’s a fountain just outside in the hall.”

“Do you have a cup of some kind?” Early asked, scanning the office.

“Let’s see.” Tattoo Cheeks spun to the left and right. “You can have my coffee mug — here, I’ll wash it out.” She vanished into an inner room, leaving the door open.

At the sound of water running, Calder and Early both lunged over the counter, cracking foreheads in the process. Tommy mashed Zoomy’s toe when he reached over to sweep fingers along the area that wasn’t visible beneath the overhang. No keys were found.

A minute later, they helped Petra to her feet and piled back out the door, leaving the girl with blue hair looking worried.

“Can I ask if you found the person you were looking for?” she asked Calder.

“Oh!” Calder squeaked. “Yeah.”

“See you,” she muttered, dropping the T pentomino into her pocket.

When the five kids emerged from the building minutes later, they were out of breath and glassy-eyed. Zoomy, Gam’s purse under his arm, had a definite limp.

“Good visit?” Mrs. Sharpe asked, her head against the seat. “I am feeling slightly better, and I thank you all for your patience.” She nodded to the five, Gam, and Ms. Hussey.

“You kids look like you’ve accomplished something,” Ms. Hussey said, with an edge of hope-you’ve-stayed-out-of-trouble in her voice. “Well, it’s a lovely end to a very busy spring break, and — I’m sure the art will turn up. Meanwhile, you’ve seen lots of other great art,” she finished lamely.

“The key,” muttered Mrs. Sharpe.

“Which kind of key?” blurted Petra.

Mrs. Sharpe’s eyes glittered, as if Petra had surprised her.

More of those weird echoes, Tommy thought. Petra’s right, it’s strange. Wonder what made the old lady say that minutes after we’d been trying to get hold of a key?

When there was no answer, Petra pressed on with, “We love the meeting room on the top floor in your house. Um, could we possibly come back and do some more brainstorming about the theft? Like maybe one day after school this week?”

Mrs. Sharpe then startled everyone with her response. “It isn’t locked and tomorrow is Saturday,” she said. “Please stay another night,” she murmured to Gam, “and the five kids can wrap up their work.”

“Well, I guess we can do that,” Gam said, gripping her purse and eyeing Zoomy’s foot. “You’ve been so kind. Sure you’re well enough for this noisy group?”

“We’ve all been stung at one time or another,” Mrs. Sharpe murmured, “and this is no time for faintness. If art alone endures — all passes, as you know — we can press on for another day.”

Sitting up, she turned toward the kids. “You’ve been quite fearless,” she said, and the kids felt a rush of shock and pride. “And,” Mrs. Sharpe continued, lingering on the word, “there’s work still to be done. I doubt that any of us can put Humpty Dumpty together again, but good things can come from such a fall — if, that is, the right pieces are lined up, like a nose finding its place between two eyes. Or a key finding the right lock.”

The rest of the ride was silent, as all ages wondered what she meant and thought about strange puzzles made from eggshells, keys, and faces. Ms. Hussey, chilled, pictured the huge Picasso lady downtown. She hadn’t meant to pull the kids into so much danger. If she had only known …

The kids, for their part, felt as though Mrs. Sharpe knew more of what they’d been up to in the Fine Arts than she was letting on. But how? Had someone been spying on them just now?

Why does Mother Goose keep popping up? Early wondered. Does she mean William Chase? Is he the smashed egg? Or is it the Farmer? And what’s that Mother Goose rhyme about a lock and a key?

The Fine Arts is a perfect hiding spot, Petra thought slowly. And if Mrs. Sharpe has had the key all along, what should the five of us do?

Tommy thought back to Ms. Hussey grabbing Eagle’s arm in the lobby. There’s a piece missing here, something we can’t see. Does the old lady want us to figure out something before Eagle or Ms. Hussey does? And what if Ms. Hussey has gotten too close to Eagle and doesn’t know it?

Mrs. Sharpe wouldn’t let anything bad happen to any of us, would she? Calder was struck suddenly by the suspicion that Mrs. Sharpe had left them in the Fine Arts just now on purpose. How much does the art matter to Mrs. Sharpe — more than certain people in her life, people like us five? Are we in danger of getting a sting?

Looking out the window, Tommy shivered. His mom would say someone had just stepped on his grave. The passes quote — does she mean we’ll all die one day, but the art will live on? Do we want to die for art?