Cordelia did not sleep well.

For a start, Goose snored loudly in the next hammock all night long. Rude sea shanties reverberated through the floor until the small hours, and Sam appeared to be having a garrulous argument with her pillow.

When Cordelia did sleep, she had hectic dreams, sharp with sharks’ teeth and flint-eyed stares.

She woke as the first light seeped through the window, her mind blazing with an urgent thought:

The Duchess is a de Sneer!

Cordelia eased the door open quietly and peered out. A dizzying drop below, several sailors lay sprawled on the sticky floor of the inn, fast asleep. Ropes and pulleys hung in the stale air. There was no sign of the Duchess.

Cordelia considered waking Sam and Goose, but they were now sleeping deeply, and she thought it would be best to find that boy from last night and question him as quietly as possible before the Duchess woke.

She scrutinized the system of pulleys and ropes dangling outside her door, recognizing the one with the heavy hook that had dragged the boy up to the rafters. It must be the way to his room.

She hooked herself to the rope and jumped. Ropes and pulleys rushed past her in a blur. She clapped a hand over her mouth to muffle a whoop of wild delight as she soared into the rafters like a bird.

The rope brought her to a stop beside a trapdoor in the ceiling.

‘Hello … boy?’ Cordelia whispered.

She scrambled out through the trapdoor and found herself on the roof of the Kingless. The roof curved away steeply beneath her feet, leaving a small platform jutting over a sheer drop, attached haphazardly to the building with ropes and struts.

A big white X was painted in the middle of the platform, and a brass lantern hung beside the kind of iron ring that was usually used for tying boats to jetties.

The boy wasn’t here. This clearly wasn’t his bedroom. But … the Duchess had sent him up here to bed, hadn’t she?

Cordelia turned, looking for clues, and gasped as she saw the island of St Freerest spread out below her.

Along the harbour, a jumble of brightly painted buildings leaned against each other, as though trying to stay upright while full of grog. In the sparkling bay, an enormous ship was dropping anchor. Behind her, a green mountain rose out of the turquoise sea, and the sunrise colours of the island were so delicious that Cordelia felt her mouth water.

But she couldn’t be distracted by beautiful views and sunrise-coloured clouds. She had questions to ask: she needed to find the boy.

‘Where did he go?’ she muttered.

This platform perched on the Kingless’s roof seemed to be a lookout spot; a telescope pointed out across the water. Cordelia put her eye to the telescope and jumped in surprise.

In the perfect circle of the lens, she saw an island floating on the flat blue line of the sea.

She took her eye away from the instrument to squint in the direction it was pointing. On the horizon, she made out a faint shape.

Cordelia knew that there was only one other island near St Freerest on the map.

‘The Island of Lost Souls!’ she breathed. ‘It must be!’

The mysterious isle had a tidal pull that caught in her chest. She thought she saw a friendly purple wink in the sky above it, fading in the rising light.

‘Good morning, Cordelia.’ A sharp voice cut through the balmy morning.

Cordelia whipped round. The Duchess stood by the trapdoor, eyes flashing like an eagle’s.

‘I – I just came up to see the view,’ Cordelia explained, trying for a breezy, conversational tone.

The Duchess did not seem convinced. ‘And what did you see through that telescope?’ she enquired.

Cordelia paused, sensing a trap. ‘Just the sea,’ she lied.

Last night, the Duchess had said that the Island of Lost Souls didn’t exist … But this telescope was trained on it. Something suspicious was going on.

The Duchess observed Cordelia narrowly, and Cordelia felt her belly button tremble.

‘That boy told me you’re a de Sneer!’ she burst out.

The Duchess smiled in a way that was not reassuring. ‘That boy is correct,’ she said.

Cordelia found there was no space to back away, even though she wanted to put a safe distance between herself and that shark smile.

‘I won’t deny, the de Sneers have a family tradition of making things worse,’ the Duchess went on. ‘There is a long and illustrious history of my ancestors sneering at things. One is famed for scowling at Joan of Arc; another is depicted grimacing on the Bayeux Tapestry. It is said: If a de Sneer curls his lip at you, you’re bound to be on the right side of history.’

‘So you are a baddie!’ Cordelia uttered, her voice fluttering like a flag in a breeze.

‘Oh, child! The world is far more complicated than that!’ The Duchess chuckled, her shark’s-tooth earring jiggling. ‘Sometimes good people do bad things for good reasons! Some baddies come dressed as heroes in smart uniforms. And the most dangerous pirates don’t even look like pirates at all: they come in disguise, dressed as respectable gentlemen.’

Cordelia dug her nails into her palms obstinately.

‘My father wears a smart uniform,’ she growled. ‘And he’s trying to do something good: catch the Troublemakers! But you tried to stop him last night by scaring everyone off from joining him!’

The Duchess frowned, invoking the ancient lineage of grim expressions that she had inherited. Cordelia could feel the pressure of scrutiny from a de Sneer. There was something searing about her stare; it blistered.

‘You’re very observant,’ the Duchess remarked. ‘You see everything … including invisible islands on maps.’

Cordelia raised her chin defiantly. ‘You know about the Island of Lost Souls,’ she said. ‘You lied to my father. You do know where it is; your telescope’s pointing right at it. And now I know too!’

The Duchess raised one eyebrow, which was enough to cause Cordelia’s elbows to quiver.

‘Do you know whose ship that is, that’s just dropped anchor in the bay?’ the Duchess asked, pointing across the water to the hulking galleon that loomed over the other ships.

The ship’s figurehead, Cordelia saw, was a golden-haired knight wielding a shining lance, and a shield decorated with a blood-red cross.

‘That’s the Invincible – Admiral Ransom’s warship,’ the Duchess went on. ‘I’m sure he would be most interested to hear about a treasonous fugitive on the run from British justice.’

‘But he can’t arrest –’

‘For the right price, somebody could sell you out.’

The Duchess stared coldly at Cordelia.

‘What exactly are you saying?’ Cordelia asked, trying not to let the curl of the Duchess’s lip affect her knees, which were getting a little wobbly.

‘If tongues begin to wag about the English girl at the Kingless, rumour will reach the admiral in no time, and you’ll be caught. You might even be delivered to him in a sack.’

‘Alternatively … I could simply put you in a packing crate and ship you back to London with my other cargo,’ the Duchess added thoughtfully. ‘There’s a boat leaving today, and I know a sailor on board who wouldn’t ask too many questions.’

She took a step forward.

‘But, of course, it’s possible to buy people’s silence too,’ she whispered. ‘And I’ll name my price.’

Her stare was so fierce that Cordelia felt the fire of it weakening her muscles.

‘Do not tell your father where to find the Island of Lost Souls,’ the Duchess hissed. ‘Give me your word.’

The Duchess’s threat was clear: Cordelia had to keep the location of the island a secret, or the Duchess would make sure she was captured and dragged back to England.

Cordelia summoned all her strength to answer back.

‘That’s where the Troublemakers’ hideout is!’ she said. ‘They’re burning ships and terrorizing London – we’ve got to catch them!’

‘No!’ the Duchess cried, lunging for Cordelia.

But Cordelia’s trousers were made of Flocculent Cotton. In one bound, she was across the platform. The Duchess sprang after her, but Cordelia flung herself through the trapdoor and slammed it shut, throwing the catch.

She swung on to the ropes as the Duchess hammered furiously at the trapdoor. Cordelia lurched through the air, unhitched a pulley and plunged several floors at once.

‘WAKE UP!’ Cordelia yelled, kicking the bedroom door open.

Goose and Sam’s bleary faces appeared as they sat up in their hammocks.

‘WE’VE GOT TO GO – NO TIME TO EXPLAIN!’

Luckily, they had fallen asleep in their clothes, so they were ready to go.

Cordelia, Sam and Goose piled into the basket and it plummeted. With barely time to catch their breath, they trampled across several snoring sailors and burst out of the front door. In the dusty street, they could hear the Duchess’s voice fluttering like a red flag on the roof.

‘Someone’ll wake up soon enough and free her!’ Cordelia panted. ‘We’ve got to get back to Little Bear!’