Thinking this way made her feel as if her brain were tangled up into one of the complex knots from which Thomas freed himself during his acts, and she soon gave up. The fact was that they were no closer to freeing General Farnum than they had ever been. They would have to count on Rosie to do her job, or else . . .

  Well. She didn’t want to think about the or else part.

  The others were obviously just as worried and unhappy as she was. She didn’t need to be a mind reader to know that. Thomas was unusually silent, and instead of babbling on about the way to mine steel or the chemical characteristics of charcoal or how a dual-compressor engine was manufactured or any of the other billions of facts he’d read in a book, he stared moodily at the ground, biting his lip. Max cleaned her nails with one of her knives, struggling to appear unconcerned—but her hands were trembling, and she nicked herself twice. And poor Sam gripped the subway pole so tightly, he made a hand-shaped indentation in the steel, causing several people to swivel around and stare as the children hurriedly exited, a full two stops early.

  “Sorry.” Sam blushed deeply. “I was distracted.”

  “I feel like a walk anyway,” Pippa said quickly, so Sam wouldn’t feel bad. “It’s too claustrophobic down here.” The subway did feel close and small after the telegram they’d received. Pippa had the sense of many minds reaching for hers like so many clammy hands. She couldn’t relax.

  But even the late afternoon sunshine couldn’t break up the shadow that had fallen over them. They walked together as a group, but might as well have been alone. They said not a single word to one another. Occasionally Thomas stopped and looked up, and Pippa’s heart soared, thinking he’d had a breakthrough. But every time he only shook his head disgustedly and continued on, head bent, kicking at the occasional stray candy wrapper or empty tin can.

  They passed the old movie theater where earlier in the summer they’d met with Ned Spode—who had proved, ultimately, to be an agent for Rattigan. Sometimes Pippa still had nightmares about what had happened in that factory, of Rattigan’s face illumined by twisted shadows, and Spode’s mangled leg, a horrible construction of metal and muscle and skin, remodeled by Rattigan in a laboratory, just as they had been built—remade differently, stronger, stranger.

  She shook her head, as though she might physically clear her mind of the idea. Just then she spotted a cheerful-looking store across the street. A small crowd had gathered to point at various items—whoopee cushions, trick decks, exploding gum, squirting flowers—arranged in the tiered window display.

  “Hey, Thomas.” She stopped. The big red sign above the door announced: McNulty’s Novelty Shoppe. “Isn’t that the store Chubby’s always going on about?”

  Thomas looked up. For the first time in an hour, his expression cleared.

  “Come on,” she said. “Let’s go in.” When he hesitated, she nudged him with an elbow. She hated to see Thomas so upset. “You’re curious, aren’t you? Besides”—she lowered her voice—“you said yourself there’s nothing more we can do right now.”

  “Think they got any more of those stink bombs?” Max said thoughtfully.

  Pippa knew enough about Max to be deeply suspicious. “Why?”

  Max shrugged. “Was thinking maybe we’d give Emily a reason to want to leave the museum, that’s all.”

  At this, Thomas broke into a smile. “Sometimes, Max,” he said, clapping her on the back, “I think you might be the genius of the group.”

  McNulty’s Novelty Shoppe looked, on the inside, like the deranged imaginings of a mischievous twelve-year-old. Mr. McNulty also gave off the impression of youth, despite the single tuft of gray hair that stuck straight from the top his otherwise bald head, the withered flower he wore in his lapel, and the fact that he walked with a cane.

  “Welcome, welcome!” He thumped out from behind the counter to greet them. “What can I tempt you with? A nice rubber chicken? Itching powder? Exploding bubble gum? X-ray glasses? A few trick candles? Or maybe a good old-fashioned slingshot?” And he pointed at each object in question with the tip of his cane.

  “We’re just looking for now,” Pippa said. “Thanks, though.”

  Mr. McNulty leaned heavily on his cane, which was painted a bright yellow. “Look away, look away,” he cried, reaching one hand into his jacket pocket. “Just be careful. It’s all fun and games until somebody gets—Squirt.” The hand inside his pocket twitched and, all at once, a stream of water shot out from his lapel flower—straight into Pippa’s eyes.

  Pippa shrieked and stumbled backward while Max exploded into laughter.

  “That was not funny,” Pippa said, glaring fiercely at Mr. McNulty, even as she attempted to wipe the water from her cheeks.

  “Oh, come on, Pippa.” Thomas slung an arm around her shoulder. All traces of his earlier bad mood were gone. “You have to admit it was a little funny.”

  “A very little,” she said. But she still scowled when Mr. McNulty began to laugh.

  They circled the shop, stopping every so often to admire one of Mr. McNulty’s gags: a jar of peanut butter that released a spring-loaded snake when the top was unscrewed, a fake ice cube containing a cockroach. To Max’s infinite disappointment, Mr. McNulty had recently sold the last of his stink bombs and was waiting for a new order.

  “But I got something even better.” Mr. McNulty picked up a tin from a display beside the register. “Sergeant Schnorner’s Superior Sneezing Powder! One hundred percent guaranteed to get the best, the biggest, the tickliest sneezes. Want to hear a neat trick?” He didn’t wait for an answer. “Put a little powder into a balloon—just a tablespoon or two will do the trick—and blow the whole thing up nice and full. When you let go, the balloon goes shooting around the room like an airplane, giving everybody a dusting of the stuff. You should hear the sneezes! Like a lion’s roar. Like a plane engine!”

  “Thanks,” Pippa said. “But we were really looking for—” She stopped speaking when she saw Thomas’s face, which had gone paper-white. “What?” she said. “What is it?”

  Thomas ignored her. He was still staring at Mr. McNulty, transfixed and terrified, as if he’d just seen a ghost. “Airplane,” he croaked. “What did you say about an airplane?”

  “Sneezes like a lion’s roar,” Mr. McNulty said. “Like a plane engine!”

  “No,” Thomas said. “No, before that. About the balloon.”

  Mr. McNulty picked up at last on the oddness of Thomas’s expression. He frowned. “I said it zooms around like an airplane,” he said. “Like one of those crop-duster planes, letting off a spray.”

  “A spray . . .” Thomas closed his eyes and swayed on his feet, as if he was about to fall over.

  “What is it?” Pippa hissed. “Are you sick or something?”

  For a second, he didn’t respond. Then he opened his eyes again, and color flooded back into his face all at once. “The dirigible.” He turned to Pippa, grabbing her arms. “Where will the dirigible launch?”

  “The dirigible?” This was such a sudden change of topic, Pippa thought she must have misheard.

  “Yes, the dirigible,” Thomas snapped. “Where does it launch tomorrow?”

  “I don’t know.” Pippa was flustered. She had a sense of his mind moving quickly—she could feel it, whirling and whirling, like a carousel spinning so quickly all the individual horses became a blur. “I can’t remember what the radio said. Some big factory on Staten Island—” She broke off, inhaling sharply.

  “That’s where all the poison’s been going,” he said. “That’s why Mallett couldn’t get any of the ingredients to make Fleas-B-Gone. And that’s why he and Erskine were killed—because they were asking too many questions.”

  “I don’t understand,” Sam said, even as Pippa did understand. Finally—she knew, she saw it, the missing piece, and a pit yawned open in her stomach.

  Thomas dropped Pippa’s arms. He turned to Sam, looking suddenly exhausted. “The dirigible,” he said, lowering his voice so that Mr. McNulty
wouldn’t overhear. “He’s going to load up the dirigible with reaper gas and let it loose over the city. He’ll kill thousands—tens of thousands. Maybe more.”

  “He . . . ?” Sam’s eyes went wide. “You don’t mean . . . ?”

  “Who else?” Thomas said grimly. “Rattigan.”

  “He must have been planning this for months,” Thomas said. They were on their way back to the museum. Pippa had to jog to keep pace with the rest of the group: Sam’s legs were nearly double the length of hers, Thomas was naturally quick, and Max was used to dodging and weaving through a crowd. “It must have cost a fortune to get all the materials together. That’s why he’s been robbing banks. And calling in favors, too. Whoever’s sponsoring the dirigible flight—”

  “Woodhull Enterprises,” Pippa interjected.

  “Woodhull Enterprises, yeah. They must be in Rattigan’s pocket. Maybe they owe Rattigan a favor from long ago, before the war. Of course, they don’t know what he’s planning to do.”

  “So that rat-faced guy who nearly kidnapped you at the bank—?” Pippa said.

  “Working for Rattigan,” he said. “Just like you thought. And he was spotted outside Erskine’s apartment, too, the night Erskine was killed.”

  “It wasn’t a coincidence,” Pippa said.

  “But how do we stop him?” Sam said, dodging a man’s hot dog cart, hands up so he wouldn’t accidentally overturn it. “If Rosie wouldn’t listen about Barrensworth—”

  “Forget Rosie,” Thomas said. “There’s no time to try and persuade her. Dumfrey will have to go to the police. I know,” he added, when Max made another face. “But we have no choice. The dirigible launches tomorrow. And you heard what Chubby said. Half the city is planning to turn out.”

  Pippa had a sudden image of the vast dirigible whirring above the city, casting the streets in shadow, and all the people clustered on rooftops and sidewalks to see it—kids, families, babies, grandmothers—as the poison went hissing through the air . . . unseen . . . unnoticed . . .

  Her stomach rolled into her throat.

  New York would turn into a graveyard.

  Sam was the first through the front door, shoving so hard it smacked against the interior wall and dislodged a large portion of plaster. But he was so consumed with thoughts of Rattigan and his terrible plan, he didn’t even feel guilty.

  Uncharacteristically, the twins were sitting behind the ticket desk, enjoying a rare moment of peace and painting each other’s nails an awful shade of crimson that, against their alabaster skin, looked just like blood.

  “Where’s Dumfrey?” Sam burst out. “We need to talk to Dumfrey.”

  Caroline barely flicked her eyes in their direction. “Gone,” she said simply.

  “Gone?” Thomas parroted. “What do you mean, gone?”

  Caroline rolled her eyes. “You don’t expect me to define the word, do you? Hasn’t Monsieur Cabillaud taught you anything?”

  Max made a growling noise and took a step forward. “Listen, you overcooked piece of—”

  “Max.” Pippa put a hand on Max’s shoulder, presumably to keep her from jumping over the ticket desk and clocking Caroline directly in the nose. She turned back to the twins.

  “Where did he go? Please. It’s important.”

  Caroline rolled her eyes. “If you must know,” she said, “he’s gone to visit Farnum in jail. Afterward, he’s going to—ahem—talk strategy with Rosie over dinner.”

  Quinn giggled. “I’ll bet he is, the salty dog.”

  Caroline smirked at her sister. “He told us specifically not to expect him until very late.”

  Max said a curse word that cannot be reprinted on the page. Thomas spun around and aimed a kick at nothing. Pippa stood very still, her lips pinched so tightly together they looked as if they’d been sewn to her face. And Sam’s heart dropped, stonelike, to the bottom of his stomach. The cops would never listen to them. They were running out of time—and options.

  “We’ll have to go to the police ourselves,” Pippa said, voicing his thoughts aloud. Sam wasn’t sure whether it was related to Pippa’s powers, but she seemed always to know what other people were thinking, even when she wasn’t reading minds.

  “But—” Max began to protest.

  “I know what you’re going to say,” Pippa said, even before Max could finish. “They’ll probably just laugh at us. But we have no choice, do we? We can’t exactly expect to track down Mr. Dumfrey on his date. He could be anywhere in Manhattan!”

  “I say we go straight for Staten Island,” Thomas said in a low voice. “Woodhull Enterprises owns half of Bay Street. And we have to destroy that airship.”

  “But how?” Pippa cried. “You said yourself, Woodhull Enterprises is in Rattigan’s pocket. He has friends everywhere. How are we going to stop him?”

  “We’ve stopped him before,” Thomas said. His eyes were very dark. “Besides, what other choice do we have?”

  For a second, Sam almost hoped that Pippa would continue to argue. The idea of going up against Rattigan was bad. The idea of what would happen if they failed was far, far worse.

  But Pippa just gave a small nod, and Sam knew, too, that Thomas was right. They had run out of options. Soon, they would be out of time. It was up to them.

  Even as Thomas was reaching for the door handle, however, the door flew open, forcing him to spring backward with a yelp. A glowering Monsieur Cabillaud stood in the doorway, hands on his hips, his tiny bald head mottled with color.

  “Aha! Zer you are!” he cried. “I have been looking for you everywhere! Naughty, naughty students.” He waggled a finger. “You think you can just forget about ze studies, is zat it? You think you can make Monsieur Cabillaud forget. But you are in error, mes amis! Upstairs, now, and quickly. Zer is still an hour for a lesson before ze bedtime.”

  “A lesson? Now?” Sam cried. Frustration squeezed like a fist in his chest. “But, you don’t understand. We can’t possibly study now.”

  “And why is zat?” Monsieur Cabillaud crossed his arms.

  “Okay, look.” Thomas stepped forward. He took a deep breath. “The truth is going to sound crazy. We’re trusting you with a secret. A big secret, okay?” He looked at the others for support, and Sam nodded. “It has to do with Nicholas Rattigan.”

  Monsieur Cabillaud’s neatly plucked eyebrows shot upward. “Ze scientist?”

  Thomas nodded. “We know where he is. And we know he’s planning something—something big.”

  “I see,” Monsieur Cabillaud murmured. “And I suppose zat you are ze only people who can stop him?”

  “Exactly,” Thomas said, nodding so vigorously his glasses jogged on his nose. “That’s just it.”

  “Mmm. And I also suppose zer is no time to lose?”

  Sam felt a heady rush of relief. Cabillaud understood. “No time at all,” he said.

  “I see, I see. Zen what I say to you, mes amis, is”—Monsieur Cabillaud leaned forward, as though to tell them a great secret, and they all leaned forward with him—“NICE TRY!”

  He screeched the last words so loudly that all four children jumped.

  “Despicable lies,” Monsieur Cabillaud cried. “Unspeakable fictions. Upstairs, all of you, now, or I will see to it zat you are locked into the museum for ze rest of ze month!” He herded them toward the stairs, still shrieking, his chest puffed up in outrage. “Allez! Ze dates, please, of ze French Revolution . . .” Monsieur Cabillaud kept them at it all through dinnertime. Soon after, Miss Fitch directed them straight to bed, and they had no choice but to go through the ritual of changing into their pajamas and brushing their teeth and pretending to fall asleep. Sam lay with his blankets pulled all the way up to his chin, as if that might stifle the sound of his heart—which was going so hard he worried the noise might prevent the other residents from sleeping.

  And, in fact, it seemed to take everyone far longer than usual to settle down. Sam felt time passing like the crawl of an insect on his skin. But at last, the final light wa
s extinguished and the attic room was filled with gentle snoring and the occasional rustle of sheets as someone turned over.

  Sam glanced over at Thomas. Even in the darkness, he could see Thomas’s eyes were wide open. Thomas nodded to him, and together they slipped carefully out of bed. Sam peeked over the top of the bookshelves that kept their sleeping area separate from Max and Pippa’s and found the two girls already standing in street clothes. Sam had stored his shoes and clothing beneath his bed and changed quickly, hardly paying attention to what he was doing. His thoughts were already outside, flying down the streets, leaping over the water to Staten Island. Would they be in time?

  They took the performers’ staircase, which carried the risk of bringing them directly past Mr. Dumfrey’s office on the second floor and Miss Fitch’s quarters below it, but it was much quieter than the vast, echoey marble staircase used by the general public. Outside Mr. Dumfrey’s office, Sam paused, pressing an ear to the door, which was open a crack. Mr. Dumfrey’s office was silent. He still had not returned to the museum, though it must have been close to midnight.

  They really were alone.

  “Come on.” Max stood on tiptoe to whisper to him, and for a brief second—a second so quick it might just have been his imagination—he thought she took his hand.

  The Hall of Worldwide Wonders was cool, dark, and so quiet Sam could hear Max’s breathing behind him. Sam felt as if he were moving through an enchanted tomb. The glass display cases winked in the faint light coming through the windows from the street, and the dark treasures nestled inside of them seemed like buried hearts, pulsing with an invisible energy. On the ceiling above them, the reconstruction of a prehistoric pterodactyl, enormous wings spread midflight, creaked lightly on its suspension wire.

  They were about to pass into the lobby when Sam heard something, a muffled cough or a footstep, behind him. He froze.