Deryn snapped to attention with the others, but her glare stayed fixed on Fitzroy. He was stronger than her, but in the two tiny bunk rooms that the middies shared, there were a hundred ways to take revenge.

Then Captain Hobbes and Dr. Busk entered the mess behind Mr. Rigby, and her anger faded. It wasn't often that the master of the Leviathan, much less the ship's head boffin, addressed the lowly middies. She exchanged an anxious glance with Newkirk.

"At ease, gentlemen," the captain said, then smiled. "I'm not bringing you news of war. Not today, at least."

Some of the other middies looked disappointed.

A week ago Austria-Hungary had finally declared war on Serbia, vowing to avenge their murdered archduke with an invasion. A few days later Germany had started up with Russia, which meant that France would be next into the fray. War between the Darwinist and Clanker powers was spreading like a vicious rumor, and it didn't seem that Britain could stay out for long.

"You may have noticed London underneath us," the captain continued. "An unusual visit, and that's not the half of it. We'll be setting down in Regent's Park, near His Majesty's London Zoo."

Deryn's eyes widened. Flying over London was bad enough, but coming down in a public park was going to stir the pot for sure. And not just for Monkey Luddites. Even old Darwin himself might have got antsy about a thousand-foot airbeast landing on his picnic.

The captain crossed to the windows and looked down. "Regent's Park is at best a half mile across, a bit more than twice our length. A tricky business, but the risk is a necessary one. We're taking aboard an important guest, a member of the zoo's staff, for transport to Constantinople."

Deryn wondered for a moment if she'd heard right. Constantinople was in the Ottoman Empire, clear on the other side of Europe, and the Ottomans were Clankers. Why in blazes would the Leviathan be headed there now?

The airship had spent the last month preparing for war -  combat drills every night, and daily musters of the fl¨¦chette bats and strafing hawks. They'd even flown within sight of a German dreadnought in the North Sea, just to show that a living airship wasn't scared of any pile of gears and engines.

And now they were headed off on a jaunt to Constantinople?

Dr. Busk spoke up. "Our passenger is a scientist of great renown, who'll be undertaking an important diplomatic mission. We will also be bringing cargo aboard, of a delicate nature. It must be treated with the utmost care."

The captain cleared his throat. "Mr. Rigby and I may have to make a difficult decision about weight."

Deryn took a slow breath. Weight ... so that's what this was about.

The Leviathan was "aerostatic," Service-speak for being the same density as the air around it. Maintaining this balance was a fussy business. When rain collected topside, water had to be dumped from the ballast holds. If the ship expanded in the hot sun, hydrogen had to be vented off. And when passengers or extra cargo came aboard, something else had to be taken off - usually something useless.

And there was nothing more useless than a new midshipman.

"I shall be reviewing your signals and navigation scores," the captain was saying. "Mr. Rigby will weigh in on which of you are paying the most attention in lectures. And, of course, any missteps during this landing will be frowned upon. Good day, gentlemen."

He turned and strode from the room, the head boffin leaving with him. There was a moment of silence as the middies absorbed the news. In a few hours some of them might be gone from the Leviathan for good.

"All right, lads," Mr. Rigby snapped. "You heard the captain. We're about to land on an improvised airfield, so look smart! They've got a ground crew in from the Scrubs, but no landing master with them. And our passenger is going to need help down there. Mr. Fitzroy and Mr. Sharp, you two are the best with the Huxleys, so you'll head down first... ."

As the bosun gave his orders, Deryn looked at the other middies' faces. Fitzroy returned her gaze coolly, and she didn't have to guess what that bum-rag was thinking. She'd been aboard the Leviathan barely a month, and it was only by freak chance that she was here at all. Not much better than a stowaway, as far as Fitzroy was concerned.

Deryn glared right back at him. The captain hadn't said anything about who'd been aboard longest. He was looking at airmanship, so he wanted to keep his best men.

And that's exactly what she was, man or not.

Maybe all the competition on the Leviathan would serve her well now. Thanks to Da's training, Deryn had always beat the other middies with knots and sextants. And even Mr. Rigby would admit that her behavior hadn't been as rowdy lately, and he'd just complimented her work with the Huxleys.

As long as the landing went brilliantly, there was nothing to worry about at all.

Regent's Park spread out beneath Deryn, its grass thick from the August rains.

Squads of ground men ran across it, shepherding the last few civilians out of the landing area. A thin line of policemen clung to the edges, holding back hundreds of gawkers. The Leviathan's shadow lay across the trees, and the air trembled with the engines' hum.

Deryn was descending fast, aiming for the intersection of two footpaths, where a local chief constable was awaiting orders. A message lizard rode on her shoulder, its sucker-feet tugging at her uniform like the claws of a nervous cat.

"We're almost there, beastie," she said soothingly. She didn't fancy arriving on the ground with a panicked lizard, the captain's landing orders garbled beyond understanding.

Deryn was a bit nervous herself. She'd ridden ascenders a half dozen times since joining the Leviathan's crew - she weighed the least of all the middies, and could always coax her beasts the highest. But that had been on U-boat spotting duty, with the Huxley cabled to the airship. This was the first time she'd free-ballooned since her wild ride as a recruit.

So far, at least, it had been a textbook descent. The airbeast's extra ballast was bringing it down fast, guided by a pair of gliding wings attached to her rig.

Deryn wondered who was so important, to warrant all this trouble. They were ruining a hundred picnics and risking disaster by landing here in the park, and probably scaring the clart out of every Monkey Luddite in London. And all just to get some scientist to Constantinople a bit quicker?

This fellow must be some kind of clever-boots, even for a boffin.

The ground was rushing closer, and Deryn let out a slosh of ballast. Her descent slowed a squick, the spilled water sparkling in the sun as it cascaded down. The message lizard squeezed a little tighter.

"Don't you worry, beastie," Deryn murmured. "It's all under control."

Mr. Rigby had told her to get down fast, with no nonsense. She imagined him watching from above, timing the descent with his stopwatch, pondering who should be cut from the crew.

It didn't seem fair to lose this feeling, not after those two long years of missing Da's balloons. Surely Rigby could see that she'd been born to fly.

A crosswind ruffled the Huxley, and as Deryn pulled it back on course, a horrible notion struck her. If she were the unlucky middy, would this be her last time in the air? With war coming, surely they'd stick her on another airship. Maybe even the Minotaur, where Jaspert was serving.

But the Leviathan felt like part of Deryn now, her first real home since Da's accident. The first place where no one had ever seen her in a skirt, or expected her to mince and curtsy. She couldn't lose her position here just because some boffin needed transportation!

The ground men were running along in the Huxley's shadow, ready to reach up and grab its tentacles. She tipped the gliding wings back to slow the descent, easing the air-beast down into their grasp. There was a jolt as they pulled her to a halt, and the message lizard made a squawk.

"Constable Winthrop?" it babbled.

"Hang on another minute!" she pleaded. The lizard made a tut-tut noise, sounding just like Mr. Rigby when the middies were squabbling. She hoped it wouldn't start jabbering. Message lizards could babble old snatches of conversation when they were nervous. You never knew what embarrassments they'd repeat.

The ground men pulled the Huxley steady and drew it quickly down.

She unstrapped herself from the pilot's rig and saluted the chief constable. "Midshipman Sharp reporting with the captain's lizard, sir."

"That was a smart landing, young man."

"Thank you, sir," Deryn said, wondering how to ask the constable to pass this sentiment on to Mr. Rigby. But the man was already tugging the lizard from her shoulder. The beastie started to babble about landing ropes and wind speeds, rattling off instructions faster than a dozen signalmen.

The constable didn't look as though he understood half of what the lizard was saying, but Fitzroy would be here soon to help. She spotted his ascender landing not far away, and was pleased that she'd beaten him down.

The airship's shadow fell across them then, and men began to scramble in all directions. This was no time to dally. Fitzroy was in charge here; it was Deryn's job to prepare the boffin's cargo for loading.

She saluted the chief constable again, glanced up at the airship looming overhead, and took off for the zoo at a run.


His Majesty's London Zoo was squawking like a bag of budgies on fire. Deryn skidded to a halt at the entry gate, stunned by the tumult of hoots and roars and shrieks.

To her right a troop of monkeys clung to the bars of their cage, howling into the air. Past them a netted enclosure was full of agitated birds, a blizzard of plumage and noise. Across a wide moat a giant elephantine stamped the ground nervously, sending tremors through Deryn's boots.

"Barking spiders," she swore softly.

She'd made Jaspert take her to the London Zoo five weeks ago, fresh off the train from Glasgow. But on that visit she'd heard nothing like this ruckus.

Obviously the Leviathan had put the beasties in a state.

Deryn wondered how the airship must smell to the natural animals. Like a giant predator coming to gobble them up? Or some long-lost evolutionary cousin? Or did its tangle of fabricated species make them think a whole island was floating past overhead?

"Are you my airman?" a voice called.

Deryn turned to see a woman wearing a long traveling coat, a valise in one hand.

"Pardon me, ma'am?"

"I was promised an airman," the woman said. "And you appear to be in uniform. Or are you simply here to throw peanuts at the monkeys?"

Deryn blinked, then realized that the woman was wearing a black bowler.

"Oh ... you're the boffin?"

The woman raised an eyebrow. "Guilty as charged. But my acquaintances call me Dr. Barlow."

Deryn blushed, bowing a little. "Midshipman Dylan Sharp, at your service."

"So you are my airman. Excellent." The woman held out the valise. "If you would be a dear, I'll just fetch my traveling companion."

Deryn took the bag and bowed again. "Of course, ma'am. Sorry to be so thick. It's just that ... no one told me you were a lady."

Dr. Barlow laughed. "Not to worry, young man. The subject has occasionally been debated."

With that she turned away and disappeared through the gatehouse door, leaving Deryn holding the heavy valise and wondering if she was seeing things. She'd never heard of a lady boffin before - or a female diplomat, for that matter. The only women who tangled with foreign affairs were spies, she'd always reckoned.

But Dr. Barlow didn't quite have the air of a spy. She seemed a bit too loud for a job like that.

"Careful now, gentlemen," her voice boomed from the gatehouse.

Emerging from the door were two young boffins in white coats, carrying a long box between them. The men didn't introduce themselves to Deryn. They were too focused on taking small, cautious steps, as though the box were packed with gunpowder and good china. Sprigs of packing straw poked out between the boards.

No wonder the Leviathan was landing smack in the middle of London - this mysterious cargo was too fragile to stick on a horse cart.

Deryn stepped forward to lend a hand, but hesitated when she felt a squick of heat rising from the box.

"Is something alive in there?" she asked.

"That's a military secret," said the younger of the two boffins.

Before Deryn could answer, Dr. Barlow burst from the gatehouse, pulled along by the oddest fabricated beastie that Deryn had ever seen.

The creature looked like a sleek tan dog with a long snout, and tiger stripes on its rump. Straining against the leash, it stretched out to sniff Deryn's offered hand. As she stroked its head, the beastie leaned back on its strong hind legs and hopped once in place.

Did the animal have a squick of kangaroo in its life thread?

"Tazza seems to like you," Dr. Barlow said. "Odd. He's usually shy."

"He's very ... enthusiastic," Deryn said. "But what in blazes is he for?"

"For?" Dr. Barlow frowned. "Whatever do you mean, Mr. Sharp?"

"Well, he doesn't look like a hydrogen sniffer. Is he some sort of tigeresque guard dog?"

"Oh, heavens!" The woman laughed. "Tazza isn't fabricated, and he isn't for anything. Except that I hate traveling without him."

Deryn pulled her hand away and took a step back. "You mean, that beastie's natural?"

"He's a perfectly healthy thylacine." Dr. Barlow reached down to scratch between the bouncing creature's ears. "Commonly known as the Tasmanian tiger. Though we find the comparison to cats a bit infuriating, don't we Tazza?"

The thylacine yawned, its long jaws opening as wide as an alligator's.

Dr. Barlow had to be joking. The creature didn't look natural in the least. And she was taking it along as a pet? Tazza looked heavy enough to displace at least one unlucky midshipman.

But it seemed undiplomatic to point that out, so Deryn cleared her throat and said, "Maybe we should get onto the field, ma'am. The ship'll be down soon."

Dr. Barlow gestured to a steamer trunk resting by the gatehouse door. A covered birdcage was sitting on top. "If you'd be so kind, Mr. Sharp."

"Yes, ma'am," Deryn sighed. She tucked the valise under one arm and lifted the birdcage in that hand. The trunk weighed almost as much as she did (another middy gone), but Deryn managed to lift one end and drag it along. The four of them - and Tazza the thylacine -  headed back into the park, the boffins carrying the box at a snail's pace.

As they made their way toward the airship, Deryn grumbled under her breath. It was one thing giving up her berth for a renowned boffin on a secret mission, but if some daft beastie named Tazza was going to take her place, the world had gone completely barking spiders.

Dr. Barlow clicked her tongue. "Your airship looks unhappy."

The Leviathan was still about fifty feet up, the captain bringing her down with infinite caution. The cilia on its flanks were rippling, and flocks of fabricated birds roiled across the park, driven from their nesting coves by the airship's twitchiness.

What was the great beastie so nervous about? Deryn glanced up, remembering the squall that had almost ended her Air Service career on the first day. But the sky was cloudless. Maybe it was the gawkers surrounding the field, their bright parasols twirling in the sun.