Bert gazed out of the window of the carriage as they hurried past the grimy, gray houses of the side streets. He couldn’t really say what he felt: a strange mingling of doubt and relief. It was the kind of feeling that would only become clear in time. The horse’s hooves thundered over the cobbles, and the carriage sped up, making for the heart of the city. “Where are we going?” said Bert.

“First, I should explain what I’ve found out,” said the Professor. “This hand of yours is a lot more trouble than I was expecting. I’ve quizzed all of my contacts, and it turns out that mirror you looked into wasn’t taken from any expedition in the official records.”

“What does that mean?”

“It means it was taken from somewhere very unusual. I suppose I should have expected as much after what happened in the museum—I’ve found a lot of magical objects that respond to simple touch commands, or the will of the person using them, but for things to come alive like that on their own is unheard of. Something strange is at work.”

Bert shook his head. It still felt weird to talk about magic.

The Professor seemed to read his mind. “I know this is all odd,” he said. “But we have to focus on the things we do know. Firstly, that the mirror did something to you. Secondly, that Prince Voss isn’t very happy with you, and that usually means something unpleasant.”

Bert nodded. “We need to get out of here.”

“Right,” said the Professor. “But first we need to find out as much as we can about that mirror. Now, I think I have a way of doing just that. But it won’t be easy.” He bit his thumb for a moment, then hammered on the hatch at the front of the carriage.

The hatch slid open to reveal Finch holding the reins of the horse in one hand and a half-eaten apple core in the other. “What’s the problem?” she said.

“How long until we reach the bank?” asked the Professor.

“Maybe five minutes. Do you have a plan yet?”

The Professor slid the hatch closed without replying. “Anyway, I was saying about the mirror. It might not be in any official records, but I know where they keep the unofficial ones. The tricky thing will be getting access to them. That’s why we’re going to the bank.”

“Which bank?” said Bert.

“Hammerton National,” said the Professor.

Bert swallowed. The Hammerton bank was in the center of the city, right next door to the highest law courts and the main government buildings. “Is that safe?” he said.

The Professor ducked down suddenly.

Bert was about to ask what was the matter when he caught sight of a group of soldiers on the road ahead. There was a whole platoon of them. They appeared to be climbing into battle wagons—a type of fast, horse-drawn carriage with space for riflemen to stand on top.

It was only after the soldiers were well behind them that the Professor sat up again. “Don’t mind me, Bert,” he said. “Just keeping a low profile.”

“Why are there so many soldiers around in the streets?”

The Professor smiled unconvincingly. “Don’t worry about that,” he said. “The military might have some idea that I’m still in the city. It hasn’t been easy getting all of this information, Bert. Who would have thought getting a pair of legs would cause so much trouble?”

There was a thump from the front of the carriage.

“Not that I’m complaining, of course,” said the Professor. “And I really am sorry you got caught up in all of this. I promise we’ll do our best to make things right.”

Bert felt a sinking feeling in his stomach. He already knew he was a fugitive, in a way, but the sight of the soldiers unnerved him. “So you’re sure this bank has what we need?”

“Certainly,” said the Professor. “And I’m afraid we can’t leave without it.”

Bert frowned. “But you just said that the soldiers are already looking for you. Aren’t they likely to catch you if you walk into a bank and ask for something?”

The Professor laughed heartily. “I’m not going to ask for it,” he said. “I’m going to steal it, Bert. In fact, with a bit of luck, you’re going to steal it for me.”

Finch brought the carriage to a halt at the front steps of the bank. Crowds of people in fine clothes passed on the broad sidewalk, and a steady procession of carriages rattled along the roads. In the distance Bert could make out a government airship floating toward the port. The entrance of the bank was flanked by marble columns, and the structure rose to an enormous domed roof.

“You look like such a tourist,” said Finch as she opened the door.

Bert was too stunned to respond to her taunting. He’d heard a lot about the rich district, but he’d never seen it for himself. The buildings seemed too grand to be real.

“I’ll be counting on you, Finch,” said the Professor. “Keep the carriage on standby for as long as possible. Try not to draw too much attention.”

“I wish I was going in with you,” she said.

The Professor hugged her, and she leapt back onto the carriage.

Bert began to get knots in his stomach. It seemed ridiculous to even dream of stealing from this marble fortress in the heart of the city, especially in broad daylight. There were thick bars on every window. “What are we actually trying to take from here?” he asked.

“That is a very good question,” said the Professor. “I have reason to believe that there is a vault here that’s used for business relating to Ferenor.”

“Why would they keep it in a bank?”

“Because it’s a secret,” said the Professor. “In fact, it belongs to the royal family, I believe. Probably someone you had the misfortune to meet recently.”

“Prince Voss?”

The Professor nodded.

Bert paused on the steps. “We’re stealing records on magical artifacts, at the city’s main bank, from Prince Voss, with the main government buildings just a few blocks away?”

“Don’t shout it all over town, Bert,” said the Professor.

They were greeted at the door by a man in a red coat, who invited them into a large foyer. Bert had never seen such a richly decorated room. The floor was marble, and the ceiling was trimmed with gold borders and elaborate designs. “Where do we go?” said Bert.

“Let’s just loiter by the line for a moment,” said the Professor.

They stood at the back of the line in front of the cashier desks. There were a lot of people ahead of them. Bert kept looking at his feet to avoid the gazes of the security men.

“I have two plans, Bert,” muttered the Professor. “But I can’t decide.” He held out his hands. “I need you to pick one for me. Right plan, or left plan.”

“Me?” said Bert. “You’re asking me to choose?”

“Beginners have more luck,” said the Professor. He looked amused.

“Fine,” said Bert. He pointed to the Professor’s right hand.

“I see,” said the Professor, frowning. “Well, we’ll have to try it.”

“Wait—can I pick again?”

The Professor shook his head. He passed Bert a small metal sphere and said: “Get rid of this in the wastepaper bin over there. It’s weighing me down.”

“What is it?”

“Just some junk I’ve been carrying.”

Bert hesitated, sensing a trick, but he could see there was no point in arguing. He crossed the polished stone floor to the bin. The only person nearby was a security guard, sitting next to a metal door with a sword at his hip. Bert took the sphere out, wrapped it in a handkerchief, and threw it in with the rubbish. He returned to the Professor. “What shall I do now?”

The Professor nodded toward the security guard by the metal door. He lowered his voice and said: “There’s about to be a distraction. Stay close.”

“What kind of distraction?” said Bert.

“Well, I’m afraid I’m a bit of a liar. I just told a man in the line that the bank is going out of business. I’d imagine he’ll be eager to get his money out.”

Even as he spoke there was a murmur from the waiting customers. “If he’s getting his money I want all of my money out too,” yelled a high voice. A jumble of protests broke out, and the crowd surged forward to demand their money from the cashiers.

“How will that help?” said Bert.

“It won’t, much. But then there’s your distraction.”

“My distraction?” said Bert.

“The smoke bomb you just planted,” said the Professor.

Bert’s eyes widened in horror. The wastepaper bin across the room ignited with a sudden hiss and spewed a cloud of dense, pungent smoke. The plumes filled the room, and the customers and staff staggered around in panic.

“Now we move—fast,” said the Professor.

Bert ran through the smoke with the Professor. People were coughing and shouting all around them. The Professor grabbed the security guard by the collar and said: “Why aren’t you helping to clear the place? Go find the manager this instant.”

The guard muttered something between coughs, then stumbled back and disappeared into the mass of gray. The metal door was left unguarded.

“Isn’t it locked?” said Bert.

The Professor twirled a set of keys around his finger. “I’m not a great pickpocket, Bert,” he said. “But you don’t have to be when there are so many distractions.” He opened the door and led Bert into a long corridor with glass windows at either side. Beyond the windows, rows of clerks were hard at work at their adding machines, oblivious to the chaos outside.

“I didn’t think it would be this easy,” said the Professor, laughing. His smile dropped as they came to three metal gates. “Oh,” he said. “What’s this?”

“Isn’t this the right way?” said Bert.

The Professor sighed. “I think I know what’s going on here. Two of the doors are alarmed. It’s supposed to trick any opportunists. But which do we choose, Bert?”

“I don’t know,” said Bert. He felt exasperated with the Professor. “Why on earth have you brought us here if you don’t know the way?”

“Just have a guess,” said the Professor.

“I’m not guessing again,” said Bert. “It’s too dangerous.”

The Professor looked puzzled, then gave Bert a shove. The push carried him toward the middle gate, but some instinct told him to dive to the left at the last moment. He braced and clattered against the bars, and the gate swung open in his hands.

They waited and listened.

“No alarm,” said the Professor. “Beginner’s luck again, Bert. But I’m afraid you have to do the last part alone. I’m going to try and secure our escape route.”

“You pushed me,” said Bert.

“I was just encouraging you,” said the Professor. He passed Bert a key, a large bag, and a diagram. “Tell the guard down the hall that the password is verdigris, and that you’re a messenger boy on an important errand for the government. Say it’s urgent. He’ll lead you to it himself.”

“Where did you get this key?” said Bert.

“That’s another story for another day,” said the Professor. “Look at the diagram once you’re inside the vault and it will show you what files to throw in the bag. I know this is all new to you, Bert, but there’s really no other way. Just try to focus and do your best.”

Bert took a deep breath. “All right,” he said. He tried to hide his shaking hands by putting them in his pockets, but his voice still quavered.

“Oh, and one other thing,” said the Professor.

“What is it?”

“Try to enjoy it, Bert. We don’t rob banks every day.”

Bert frowned in annoyance, but the Professor had already gone.

He moved as fast as he dared down the long passageway, feeling painfully aware of the sound of his footsteps on the hard, polished floor. As he rounded a bend he found himself face-to-face with a guard sitting at a metal desk. “Yes?” said the man.

“I—I need to see a vault,” he stammered. “The password is verdigris.”

“You’re here alone?” asked the guard.

“I’m in a hurry,” said Bert. “Files for the prince.”

“Does the manager know you’re here?”

Bert thought for a moment about the best response. He held out his palm and showed the man the key. “No,” he said sarcastically. “I broke in.”

The guard laughed. “Very funny, young sir, but you can’t be too careful. Stranger things have happened in Ferenor, as my father used to say.”

Bert tried to look like this was all routine to him as the guard led him through several more gates, locking each one behind them. Then he opened the vault.

“I’ll be waiting for you here, sir,” he said.

“Thank you,” said Bert. He stepped inside the dark space, and the door closed behind him with an ominous clang. It took a moment for the amphor lights to ignite.

The room was almost circular, and much bigger than he’d expected. Tall paintings of strange landscapes hung along the curved walls, while a ring of shelves nearby held all kinds of curiosities—from simple vases to the kind of complex machines he’d seen in the museum. He noticed one row that held various metal hands, some of which were tipped with edged weapons. Another cabinet was filled with strange glowing orbs that seemed to give off heat. There were books and notes everywhere too, and a whole quarter of the wall covered in maps of Ferenor.

His gaze was drawn to a long shelf arrayed with a collection of large lanterns, like the ones he’d seen at the museum. There were countless diagrams alongside them with revisions and notes—something about using crystals to cast the right sort of light. One diagram showed an airship directing a large lantern toward a cloud; another showed a picture of a large castle.

He couldn’t make any sense of them.

He noticed a desk with a pen and an uncovered inkstand in the center of the room, and realized with a stab of panic that someone might have been using the vault recently. The thought that Prince Voss himself might walk in at any moment brought his fears to life.

He hurriedly began to follow the Professor’s instructions, counting his paces until he came to a set of filing drawers. Inside were rows of dated entries, some of which had the names of airships printed across the top, others with long series of numbers. He tossed all of them into the bag and took a few deep breaths, reassuring himself that this was the right thing to do. He had never stolen anything before. Diving straight into capital crime wasn’t easy for him.

As he made his way back toward the door he noticed a large painting on the wall. It showed a green landscape, and far above it a large castle floating in the clouds.

He was struck by the detailing of the picture.

There was a note beside it, with pictures of various airships and the names of their captains. Some of the names Bert vaguely recognized. There were crosses through all of them except one: Professor Roberts. It made Bert feel uneasy, but it also reminded him that the Professor was waiting. He moved on quickly, lugging his heavy bag over his shoulder.

Just then he heard the vault door open.

Bert flinched, and looked up.

Three security guards were waiting for him at the doorway. One of them was holding the remains of the metal sphere that had started the paper bin fire.

“Come with us, please, sir,” said the guard who’d let him into the vault. “There are some people out here who have some questions for you.” He took the bag from Bert’s grasp. “I think they’ll be interested to see what you were trying to take from our vaults, won’t they?”

Bert’s heart sank. He put his hands in his pockets and allowed himself to be marched back to the foyer. The customers had vanished and the Professor was handcuffed to the front desk. He had a bruise on his face and his sword was gone. Around him stood a dozen men wearing long coats and short-peaked caps. Bert felt a chill in his bones. The men were clearly quæstors. Cassius stood at the center of the group, looking dangerously angry.

“Hello, Bert,” said Cassius. “I hoped I wouldn’t see you so soon.”