‘Isn’t this stealing?’ Goose wheezed.

‘Not if we return it,’ Sam replied breathlessly. ‘Then it’s borrowin’.’

The children were furiously rowing a small ‘borrowed’ fishing boat across St Freerest’s Bay.

‘I’m wanted for treason!’ Cordelia puffed, pulling on her oar. ‘What’s a little boat-borrowing when the king of England’s after you?’

Little Bear lay asleep at anchor. Cordelia, Sam and Goose climbed up the ladder on to the deck and hurried below to the captain’s cabin. They found Captain Hatmaker awake, poring over his maps.

‘Dilly, Sam, Goose!’ he cried. ‘What are you doing here?’

Cordelia quickly gasped out what had happened on the roof: how the Duchess had threatened her because she had seen the Island of Lost Souls through the telescope. Before her father had time to take in all this information, Cordelia turned to the map spread across his table. The Island of Lost Souls shone brighter than ever on the parchment.

‘You must see it!’ she cried, pointing as Sam and Goose stared blankly at the map. ‘It’s clear as day!’

Prospero was distracted by the more urgent problem at hand.

‘I thought I could trust that duplicitous Duchess!’ he muttered. ‘Now the admiral’s here, she could tell him everything.’

Prospero grimaced, striding to his window and staring at the dark blot of the Invincible in the bay.

‘Wake Melchior and Davey,’ he ordered. ‘We put to sea.’

Making a ship ready to set sail was a slow process, like waking a giant.

After leaving the Kingless last night, Prospero had not found a single soul on the island of St Freerest willing to go after the Troublemakers. So they remained a crew of six. But they knew the ropes, and they all worked quickly. Soon, the sails came down to catch the wind and Little Bear leaned towards the open sea.

Will the Duchess give us away? Cordelia wondered as they surged out of the harbour.

They met the open water with a bump. The sea was dark and stirring.

‘If there’s a storm, at least it will buy us some time if the admiral decides to give chase,’ Melchior said grimly.

‘It’s coming in from the south-west,’ said Davey, squinting up into the clouds.

‘We can go after the Troublemakers now!’ Goose joined in excitedly. ‘Cordelia saw their island – now we know exactly where to go!’

‘Yeah!’ Sam added. ‘Where’s the island, Cor?’

Cordelia pointed to the south-west. ‘That way!’

But the sky was painting itself grey before their eyes. Frowning clouds clotted the horizon as the sea grew teeth, gnashing at Little Bear with strange serrated waves.

‘There’s something freakish about this sea,’ Davey muttered. ‘I don’t like it.’

‘We’re not going towards the Troublemakers!’ Prospero announced firmly. ‘Not with you three children on board!’

‘Why?’ Goose wailed.

Prospero adjusted his captain’s hat as the wind fretted and shoved.

‘Because I promised in the note I sent home with Agatha that I would return you to your mother in one piece, Lucas Bootmaker,’ Prospero said, fixing each of them with a stern look. ‘And you, Sam Lightfinger, to your brother. And you, Cordelia, to the rest of the Hatmakers. I promised you would all be safe! You are children and these pirates are clearly extremely dangerous.’

Cordelia, Sam and Goose burst into a chorus of objections.

‘But I saw the island!’ Cordelia protested. ‘I know exactly –’

‘I am the captain!’ Prospero had to raise his voice to be heard above the grinding waves and mutinous shouts. ‘This is my ship! When on board, you go by my rules!’

Cordelia, Goose and Sam fell into a surly silence. The wind muttered around the mast.

‘We’ll sail round the island of St Freerest to the southern shore,’ Prospero said. ‘We’ve already got supplies aboard to last a week or so. We’ll hide until –’

‘Hide!’ Cordelia burst out indignantly.

Her father was a seafaring hero! He had not hidden during any of the daring exploits he had told her about. But that was when she was safely sitting at the kitchen hearth and any danger lay leagues across the sea. Now they were on a tiny ship racing out into the open ocean, chased by a tempest.

Prospero clapped a hand to his head to stop his hat being snatched off by the wind. The sea roiled like a cauldron coming to the boil; water drew itself up into green hills, bore down like a landslide over the ship and crashed over the rail.

‘No arguing!’ Prospero bellowed, staggering sideways in the drenching drag of a wave. ‘Storm’s here! Get below!’

Cordelia, Sam and Goose stumbled below deck feeling very hard done by. They were soon distracted from their malcontent by the more urgent problem of seasickness. As they opened the door to Cordelia and Sam’s cabin, the floor fell away, and they went skidding down the sudden steep slope and piled against the far wall.

‘Argh!’ Goose moaned, lunging for a bunk but missing as the ship pitched again.

It was like being in the belly of a beast. A beast with a terrible bellyache. The ship reeled yet again. Cordelia felt as though a mean fist had grabbed her guts and twisted. With each sickening lurch of the sea, her stomach climbed up her throat.

‘I suddenly feel uncooked in the middle!’ Goose moaned.

Cordelia crawled along the rocking floor to peer out of her porthole. The sea was disobeying all its usual rules and arranging itself at very alarming angles against the iron sky.

Sam groaned as Little Bear rolled on the ocean swell.

‘When’s it gonna stop?’ she whimpered.

‘Not for a while,’ replied Cordelia. ‘We’re surrounded by sea!’

That is the problem with the sea: there is an awful lot of it, and when you’re in the middle of it, it goes in every direction.

‘I can’t swim,’ Sam admitted, fear clouding her eyes.

Cordelia’s belly dropped as Little Bear plunged down a wave into a valley of moving water. She tumbled over Goose, who was lying flat on the floor and groaning.

A solid slab of sea slapped the porthole and she fell backwards. Sam dragged her into the bunk. As Cordelia swung with the motion of the ship, the sick feeling that gripped her belly loosened a little.

‘I’m scared,’ Sam whispered, trembling, as the ship tipped sideways.

Cordelia reached for her hand and squeezed it hard as Little Bear reared and pitched over the steep waves. A great creaking sounded around them as the very bones of the ship protested.

‘Is Little Bear going ta break apart?’ Sam asked.

‘No,’ Cordelia replied decisively. ‘She’s stout and strong and she’ll weather worse storms than this.’

Sam smiled shakily. ‘I’ve weathered worse too,’ she said.

Hours later, the storm abated and the sun cracked through the clouds, dripping egg-yolk gold. Cordelia, Sam and Goose staggered up on to the sea-slick deck to gulp lungfuls of fresh, salty air.

‘At least we haven’t been blown too far!’ Cordelia said, pointing at St Freerest silhouetted on the starboard horizon.

However, breaking away from the outline of the island and chasing the ragged hems of clouds, came a ship.

‘Is that the admiral comin’ after us?’ Sam gasped.

‘Can’t be!’ Davey answered from the rigging. ‘He’d be sailing from St Freerest.’

Cordelia turned to squint at Davey. He was peering at the horizon off the port bow, at the distinct mountaintop of St Freerest. Cordelia swung round, staring at the island that she had assumed was St Freerest on the opposite horizon. It was clear: a jagged cut-out against the bright gold sky.

‘That must be the Island of Lost Souls!’ she exclaimed. ‘Look!’

Everybody peered in the direction Cordelia was pointing.

‘Where?’ Goose asked.

Cordelia jabbed her finger at the jagged island.

‘Right there!’ she cried.

After the thunderous grey of the storm, the world was gilded and glaring. The sea was a sheet of hammered copper, and light struck up into her eyes. But even through the glare, the island was clearly there.

Why could nobody else see its dark shape? It was so clear it looked almost close enough to touch.

Sam was shaking her head, and for a moment Cordelia wondered if they had all ganged up on her for a strange kind of joke.

‘Father, you can see the island now, can’t you?’ she asked. ‘It’s right there!’

Captain Hatmaker had his eye pressed to his telescope.

‘I can’t see an island, Dilly, but there’s something strange about that ship,’ he murmured.

Cordelia squinted at it. It skimmed across the glittering sea towards them, wearing the storm like coat-tails. There appeared to be silk kites flying from the rigging and a vine of huge poisonous-looking flowers twisting round the bowsprit. The sails flashed as though they were laced with quicksilver, and behind the vessel trailed several clouds, seemingly being towed on ropes. The air around the ship flared red with the wings of strange birds, and the water surging beneath the hull was alive. Cordelia peered closer and saw something strong and slippery weaving in and out of the water. It had a tail that flashed strangely, making the water bubble. Black waterspouts erupted from the ship’s wake.

‘What in the world …’ Sam whispered.

Cordelia peered into the sunset. The figurehead rushing towards them over the ocean had horns and a wicked grin.

The ship surged closer and she could make out a single word, painted in curling gold letters on the prow:

Trouble