Robert woke to find a bright light blinking down on them through the luggage rack. Beside him, Lily’s head lolled against the headrest of the seat. He checked her pocket watch. Nearly four o’clock in the morning – they would be arriving in London soon, if all was well.

At the far end of the cabin, a figure in a black coat and battered bowler hat was stepping out into the passage, pulling the door shut behind him. Instinctively, Robert felt for the Moonlocket around his neck. It was still there, thank goodness! But something wasn’t quite right…

He stood and took his cap from the coat hook above him, glancing up at the luggage rack. It was empty! He shook Lily awake. “Someone’s taken Malkin!” he cried.

Blearily, Lily pushed the hair from her face. “What? When?” The words came tightly from her throat.

“Just now. Look!”

She squeezed from their shared seat and surveyed the cabin. “The man who was sitting at the far end…”

“He’s left,” Robert said.

Lily’s chest ticked with panic as she tried to recall what the man looked like. It was no use – all she could remember was a few tufts of black hair curled round the edge of his bowler, which he’d pushed down to hide his face.

She gripped the arm of the woman next to them. “Where did that man go?” she asked, pointing at the place where he’d sat.

The woman yawned and considered the question.

“How would I know?” she said finally. “He ain’t returning, though. He took his bag. There’s been such comings and goings, some of these fellows get up every few minutes to use the water closet. It’s quite unbelievable.”

“Which way is the water closet?” Robert asked.

“Right…no, left!”

“Oh, for goodness’ sake!” Lily squeezed up the narrow footway to the door, kicking people’s feet and bags out of the way. Robert followed, almost tripping over the shoes of the last man in the row, who jolted awake, and watched with uninvolved interest as Lily pulled aside the sliding door of the compartment and let in the cold air.

“Quick!” she cried, and she and Robert raced down the corridor.

Turning sharply at the starboard end, the corridor rose up a short flight of stairs into the first-class lounge. It was dark, except for the moonlight coming in through the large viewing windows.

“There he is,” cried Robert, pointing out the man in the bowler, who was walking across the far side of the room, pulling their bag along behind him. Robert felt confused. Who was this new villain? He looked taller than Jack…

Over the soft rumble of the engine, Lily could make out Malkin’s muffled cries from within the bag. “Where’s that man taking Malkin?” she exclaimed, pushing past empty tables and chairs.

“And what’ll we do if we catch him?” Robert raced behind her, accidentally tipping over a trolley filled with cutlery, which clattered to the floor.

“Fight!”

“D’you think we can fight such a big fellow?”

“We have to! We need to get Malkin back.”

They sprinted after the figure in the dark and stumbled into another corridor that ran along the port side of the ship. The man was already far ahead of them, nearing the stern. He threw their bag down a stairwell and, holding onto his hat, hopped after it with one balletic jump that reminded Lily of a mechanical monkey.

When they arrived at the bottom of the ill-lit stairwell, they found that a narrow hatch had been forced open and could hear the man’s footsteps echoing along the passage beyond it. Robert read the sign above the doorway.

Goods Compartment and Engine Room – authorized personnel only!

As they struggled through the hatch a hot wave of stale air hit them and the hairs on the back of Robert’s neck rose involuntarily.

Lily gripped the ammonite stone in her pocket. A sense of apprehension was growing inside her. For once, she wished Papa was here to tell them the right thing to do, or Anna to encourage them.

The short passage ended in a long open chamber filled with towering stacks of trunks, roped to cleats that crisscrossed the floor. Pipes ran along the metal-riveted walls, making the room feel uncomfortably hot. A strong musty smell of steam and oil wafted over everything and, far off, they heard the clanging and chuffing of the airship’s engines.

The bag thief had disappeared; he had to be hiding somewhere in the shadowy gaps between the rows of luggage. Lily motioned to Robert and the pair of them stepped deeper into the darkness of the room.

“Where is he?” she whispered.

Robert shrugged and shook his head. “I don’t know.”

A loud shriek broke out, then a bark. A streak of orangey-white flew out from behind a travelling trunk.

Malkin! He came skittering towards Robert and Lily, scraps of torn coat clasped between his teeth.

“I bhff hmm whnn hh pppnnd thhh bgg!” he garbled.

“What?” Lily asked him.

Malkin spat the scraps out. “I said, I bit him when he opened the bag!”

The thief stepped out from behind a travel trunk, waving his hand in front of him as if he’d just burned it on the stove. His hair was dark and curly and his face was worried and pinched, but his eyes were wide and grey, the same as Jack’s. One of his sleeves was now raggedy, and blood dripped from his fingers. Who on earth was he?

“Finlo, you worm, I told you not to alert them to your presence.”

Finlo bristled and clenched a bleeding fist, as a second man stepped from the shadows behind him, blocking their exit – Jack!

A stony expression clouded his scarred face. How had he made it onto the airship? It had been delayed taking off, but only by minutes, surely? Unless… Robert remembered John’s steam-wagon on the airfield…

Jack stepped towards Robert and Lily. “You took a locket from Thaddeus’s house.”

“What’s it to you?” Lily asked.

“Merely a keepsake, a remembrance, a small memento to help me recall that which I’ve lost. We all like to recall our lost ones, don’t we, Miss Hartman? Your mother, for instance…”

Lily shook with silent rage.

“We don’t have anything of yours.” Robert raised a hand and clasped involuntarily at the Moonlocket. It felt warm and safe, tucked against his chest, beneath his shirt.

“Oh, but I think you do.” Jack’s grey eyes bored into him. “Do you know what a tell is, boy?”

Robert shook his head. He hadn’t a clue what Jack was talking about.

“It’s when you tip your hand,” Jack Door explained. “Let the other player know he holds the winning trick.” He gave a lopsided grin. “You see, I may not have taken the Moonlocket from you at Townsend’s, or at Brackenbridge, and it may not be in your bag.” He kicked it viciously and Lily was glad Malkin was no longer hidden inside. “But I know exactly where it is now. You just told me, Robert. It’s around your neck. And this time you’re going to give it up of your own free will.”

“I don’t know what you’re on about.” Robert brazened it out. “This locket belongs to my family.”

Jack laughed. “But we are your family, Robert. I’m your poor old long-lost grandpapa. And this idiot is your wayward uncle… Surely Inspector Fisk, who visited you the other day, told you that much?” He searched Robert’s face for an answer and smirked drily when he saw he was right. “He did? Jolly good!”

“No, I—”

“Don’t bother to lie to me again, Robert. I can read your face like a pack of cards. It’s always easier when everyone’s laid their hand on the table.”

“I won’t give you the locket,” Robert told him. “Whatever you say… It’s for my ma when we meet again.” He spoke loudly, but sweat was pouring down the back of his neck, and the words seemed more confident in his head. He and Lily may have escaped Jack when he was alone, but this time he had Finlo to help him. Two hard-nosed criminals and no one to come to their aid. But whatever they threatened, whatever terrible things they might be capable of, he, Lily and Malkin had to stand their ground.

“You think, if you give her the locket, she’ll be pleased to see you?” Jack motioned to Finlo, who began advancing on Robert, Lily and Malkin. “She won’t be, son. She doesn’t care. Never did. Why do you think she left in the first place, with no explanation? There’s only one reason: betrayal. She betrayed us all over the years – you most terribly, poor, dear child. And she’ll do exactly the same the next time…”

“That’s not true.” Robert felt tears gathering unbidden behind his eyes.

“Yes,” Jack said, “it is. So why put yourself at risk of that hurt? And from your own mother too? When the only thing you need to do is give me the Moonlocket.” He held out a palm.

Robert couldn’t stop. Almost as if he was hypnotized, he found himself reaching for the locket, pulling it from beneath his shirt and fumbling with the catch on the chain around his neck to take it off. Jack’s eyes gleamed at the sight of it.

“Robert?” Lily whispered. “What are you doing?”

The locket sat glistening on Robert’s palm.

“That’s it,” Jack said. “Hand it over, then you can all go home.”

Robert shook the glare from his head. “I have no home.” He closed his fingers around the locket. He would keep it. For his ma. And he would fight for that right if need be. He squared up to the men.

Jack shrugged and stepped aside; reaching Robert in an instant, he pulled at his fingers. Robert held tight to the locket, but Jack was crushing his hand. The sharp points of the moon dug into his palm like two nails.

He couldn’t grasp it much longer. He needed help, but Finlo was holding Lily and Malkin at bay. Jack prised harder, loosening Robert’s digits. For a second his fingers twitched, and Jack snatched the locket away from him.

“I have it!” Jack crowed. “The prize!” Then he saw the crescent. “Where’s the rest?” he cried. “This is only half a moon. Half the map!”

Malkin raised his hackles and growled, pulling back his lips to reveal sharp teeth. He dodged past Finlo and was on Jack, snapping at his hand, pulling the locket away in his jaws. Finlo tried to grapple it from the fox, but Lily kicked the villain in the shins and he let out a yelp and let go.

“Come on,” she cried, taking Robert’s hand. “Down this way.”

They hopped a metal joist in the floor, and squeezed through the narrow gap between towering piles of luggage. Malkin galloped in their wake, clasping the locket in his mouth.

As they emerged behind the trunks, Robert nearly tripped over a tangle of loose straps tethering them to cleats along the floor.

“Quick,” he cried to Lily. “Push!”

Robert kneeled down and undid each strap, one by one.

Lily threw her shoulder against the tower and shoved hard.

“Malkin, get behind me!” she shouted.

The cases began to shift, but they weren’t quite toppling. Not yet…

Lily butted her shoulder hard against them once more, as Robert freed the last of the ropes that held them tight, and stood to help.

Finlo and Jack were stalking round either side of the trunks towards them. When, with a loud CrRRrreaaaAAakkkk! the trunks collapsed.

Jack and Finlo threw up their arms to protect themselves, but they were caught on one side by a huge canvas trunk, which had fallen on their feet with a crash, and on the other by a heavy wooden box plastered in customs labels. The box smashed open, scattering hundreds of Edison’s talking dolls all around them.

“Hello, pleased to meet you!” the dolls squealed in high-pitched cheerful voices, their glass eyes spinning and their arms flailing wildly as they fell.

“Will you be my friend?” they cooed, their mechanical insides rattling as they bounced across the curved floor of the airship’s hull.

“Are you my mummy?” one in a pink dress and straw hat spouted.

“Dolly wants to play!” said another, hanging by her hair from a nail on the corner of the box.

“Please sing me a song,” said a third with ribbons in her hair.

“Clanging chronometers!” Malkin cried. “It’s like teatime at the orphanage! Quiet, you blathering metal babies!”

The dolls didn’t hear, or take any notice, just carried on spouting their set phrases…

Finlo and Jack tried to struggle through the mound of dolls, which crawled around their feet, waggling their little arms and grabbing at the men’s trouser legs.

“Sing with us,” pleaded one red-cheeked doll, as Jack booted her across the aisle. “Twinkle-twinkle. Twinkle, twinkle…”

Lily and Robert didn’t wait for Jack to try the same with them, but turned and ran off down the length of the luggage compartment.

Drenched in sweat, Lily searched for an exit…

“There’s no escape pod, clank it!” Malkin barked.

“They never have one on commercial zeps,” Robert wheezed, his chest aching with worry.

“Where to now?” Lily cried.

“There!” Robert shouted. “The mail hatch!”

They barrelled over to it. Robert fought with the stiff bolts and then, pulling them aside, threw the hatch open, revealing a black hole of darkness.

The airship tipped towards the port side, its nose dropping suddenly. A large box slid from behind them and toppled through the opening. After a moment there was a loud splash.

Lily ducked down, dipping her head through the hatch; screwing up her eyes against the battering wind, she glanced about.

They were somewhere over the northern outskirts of London. The zeppelin had started its slow descent, aiming for St Pancras airstation in the distance. It hung barely fifty feet above the treetops, passing over what looked like a large lake of shimmering silver water, nestled in the dip of a hilly heath.

Malkin shook Lily by the shoulder. “Hurry,” he cried. “We need a plan!”

Jack and Finlo had pushed aside the broken trunks and were wading angrily towards them through the rest of the strewn luggage and squawking dolls.

Robert picked up a stray doll and threw it at them…

It missed.

“I love you,” it said mournfully. “Will you be my mama?”

“Drop the mail line!” Lily cried as she ducked back into the gondola. “We’re going to slide down into the lake…”

“You know I can’t swim,” Robert told her.

“Neither can I,” Malkin cried. “But never mind that, you demented doohickeys, the fall will probably kill us! If you think I’m getting in another bag to be thrown out of another airship and plunged into a lake,” he snapped, “then you’ve got more cogs loose in your cranium than I’d have credited.”

“Quiet!” Robert cried. “I have to think!” He quickly tied three heavy sandbags onto the end of the mail line and threw them out of the hatch. The sandbags plopped into the lake, sinking fast.

Finlo and Jack were almost on top of them now. They were nearly out of time.

Robert let out as much line as he could. The sandbags sank deeper, reeling out the rope, which creaked and cracked. The chugging zeppelin dipped lower over the pond until it was only thirty feet above the water’s surface.

Robert snatched two large empty mailbags from the pile beside the hatch and fastened them to the line by their metal C-clips; they were good and strong, made of sturdy sacking.

“Get in,” he told Lily and Malkin.

“Here we go again,” Malkin muttered. Lily covered his snout and stuffed him into the mail sack, then she clambered in after him. The instant both her feet were in the bag, Robert pushed her off. Lily held her breath as she and Malkin went whooshing down the anchor line.

The airship rocked as the anchor rope reached the end of its tether, pulling taut. Finlo and Jack threw out their arms to steady themselves.

Robert gulped, feeling momentarily dizzy at the thought of jumping out into the dark sky. Panic washed over him – he had to go now, the others had done it, and he needed to get away from Jack and Finlo. They weren’t safe, even though they were family! He took a deep breath and climbed into the other mailbag just as Jack reached out to grab him.

Jack’s hand snatched out a hair’s breadth above Robert’s head as he shoved off against the corner of the hatch. And then, in a flurry of cold air, Robert was sliding like a shooting star across the night sky…