They landed on wooden planks with a thud. Cordelia scrambled to her feet, smelling pine timber and the tang of tar, and realized that she and Prospero had come aboard Little Bear in a rather unusual way.

A lantern flame flared, turning the evening drizzle into a pearly mist, and Cordelia saw the faces of two of Little Bear’s crew: the first mate, Melchior Brown, and Davey Fogg, the ship’s engineer.

‘Captain and Miss Hatmaker!’ Melchior Brown cried, dropping the rope he had used to hoist the Hatmakers aboard. ‘A surprising entrance, even for you!’

‘Cast off, quiet and quick – no time to explain!’ Prospero ordered. ‘Who’s aboard?’ He strode to the wheel as the two men sprang away into the rigging.

‘Just us. Jack went off somewhere – he’s not back yet,’ Davey Fogg answered from halfway along the mainsail boom. ‘Catch!’

Cordelia staggered as she caught a heavy coil of rope.

‘Lay it on deck!’

‘Jack’s not aboard?’ Prospero asked regretfully. ‘We’ve got to go now.’

Little Bear creaked as Prospero turned the wheel.

‘We’re still moored,’ Melchior Brown hissed. ‘Miss, help me with the mooring ropes!’

Cordelia dashed to the rail and began untying the ropes attaching ship to shore. In the half-dark, she saw a glimmer zigzagging along the wharves. Seconds later, someone leaped on to the gangway, streaked across it in a blur of light, and splayed on to the deck.

‘Sam!’ Cordelia gasped.

‘They’re comin’!’ Sam panted. ‘I only beat ’em cos I put Lightning Light on my heels and ran quick as wildfire.’

Sam’s boots glowed faintly.

‘Who’s coming?’ Davey Fogg called from the mizzenmast.

‘Look!’ Cordelia yelped.

Dozens of lantern flames speckled the twilight, weaving through the docks.

‘Melchior, cut the mooring ropes!’ Prospero barked. ‘Everyone else, raise the mainsail!’

In a flurry of quiet but frantic activity, everyone rushed to obey their orders. Melchior seized an axe.

‘Cordelia Hatmaker!’ came a shout from the shore. ‘Surrender immediately!’

‘Haul, on my count!’ Prospero cried as Cordelia and Sam grabbed the heavy rope behind him. ‘Two-SIX!’

They hauled – the rope tautened like a tendon.

‘Two-SIX!’

Cordelia clenched her jaw, heaving mightily. The rope strained under the massive weight of the sail. Above them, the canvas inched upwards.

‘Two-SIX!’

The mooring ropes splashed into the water as Melchior chopped them free.

‘We demand you hand over Cordelia Hatmaker!’

‘Two-SIX!’

They hauled again, muscles burning.

‘Two-SIX! Two-SIX!’

Arms worked like pistons in a machine as the sail unfurled in a slow banner above them.

‘THIS IS YOUR FINAL WARNING!’ came a furious screech from the shore. Cordelia recognized the voice of Sir Piers Oglethorne, but barely heard it over the screaming of her muscles and the thunder of blood in her ears.

‘Two-SIX!’

‘BOARD THEM!’

A dark shape swung across the rift between boat and wharf. Prospero dashed into the middle of the deck to tear the shape out of the air, propelling it over the rail.

SPLOSH!

‘We’re FREE!’ Melchior cried, chopping the last mooring rope.

The deck lurched. The gangway parted company with the wharf and fell with a splash into the water.

‘OPEN FIRE!’

Pssst! Pssst! The night whispered fiercely at them.

‘TAKE COVER!’ Prospero yelled, pulling Cordelia down behind him. Musket fire bit the mast, bringing the nip and sting of splinters.

‘She’s a child!’ he roared. ‘For pity’s sake!’

Cordelia peered, wide-eyed, over his shoulder to see musket flashes peppering the dark across a widening canyon of water.

Prospero dragged her behind him to the wheel. ‘AND HOLD ON!’

The ship bucked as Prospero wrenched the wheel round. ‘Pull that sail taut!’ he yelled. ‘We don’t have enough wind!’

An idea hit Cordelia like a hurricane. She rushed across the steepening deck, slammed into Win’s Weather Pantry and flung it open, fumbling among jostling bottles to seize a thick knotted Breeze String. She tugged the knot with her teeth – it sprang open. A whip-tongue of air cracked free, the mainsail snapped tight, and Little Bear leaped forward like a wild creature.

‘STOP!’

But the shouts from the wharves were lost in the whistling wind.

‘More of that, Dilly!’ Prospero yelled.

Cordelia undid another knot and Little Bear burst on to the wide silk of the river. The wind bellied in the sail and Little Bear chased along the Thames. Sam, still holding white-knuckled on to the mainsail rope, grinned a shaky grin. The tide was turning like an upsurge of hope beneath their hull.

‘Another, Dilly!’ Prospero eased the wheel to guide Little Bear into the mid-stream. ‘We’re not safely away yet!’

She untied knot after knot, and wind and river carried them onwards.

Davey and Melchior raised the foresail as Cordelia peered over the stern, her hair flying around her, looking out for pursuers. But their ship was too quick to catch. The master shipwright had wagered that Little Bear would be the fastest ship of her kind, and he’d been right.

The bulky shapes of buildings subsided and the land around them became empty and flat. Stars salted the sky, and all that could be heard was the rush of the river and a choir of nightbirds in the marshes.

They were soon far beyond London.

Melchior struck flint to tinder, lighting lanterns to hang on bow and stern to avoid collisions with other ships.

‘Go below to your cabin,’ Prospero suggested to Cordelia and Sam. ‘Get some sleep. We’ll talk in the morning.’

But Cordelia’s skin tingled and her stomach jumped at every noise. She would never be able to sleep. Sam stayed with her, grabbing her arm whenever the ship tilted.

They paced the deck, checking ropes, feeling for the wounds in the wood where musket balls had punctured the beautiful new ship. Davey found a musket-ball hole in his hat, inches above his left eye, and wiggled his finger through it like a worm through an apple.

Prospero kept his eyes fixed on the horizon and his hands clenched on the wheel.

That was how they sailed through the night.

Cordelia woke as dawn stroked fingers of light across her face. Sam slept beside her. Someone had covered them with a blue jacket that jingled with shiny buttons as she sat up.

England had come apart at the seams and splayed open into a sky-wide sea. The ship rode the cusp between river and ocean, nosing past great rocks upon which was perched a lighthouse.

‘Rivermouth!’ Cordelia whispered. Her breath came out in a cloud.

Her father stood at the wheel, face crumpled from lack of sleep but shoulders square with determination. Cordelia got the impression he had not moved all night. Melchior and Davey were slung in the low reaches of the rigging, watching the horizon.

Cordelia, limbs stiff with cold, tottered to the prow.

‘We need to get beyond sight of land, Cordelia,’ Prospero called. ‘Let’s have one more blast of wind to speed us out to sea.’

She tottered to the Weather Pantry, selected a large, straining Wind Bag and climbed up into the aft-rigging to open it. The wind burst out, fattening the sails with bellyfuls of air.

Little Bear nosed through the waves, leaving a frothing trail of white in the dark sea. Cordelia felt as though she was riding a slow comet blazing a trail away from the life she knew. England was soon far away on the horizon, a land made of paper floating on the ocean.

She rubbed sleep from her eyes and blinked. A different kind of celestial body was approaching. It was a pale bird, winging towards the ship.

‘Agatha!’ Cordelia cried, scrambling down the rigging as the bird descended in a graceful arc.

Agatha was a Quest Pigeon, raised from a newborn chick by Prospero, a bird so elementally connected to him that she could fly to find him anywhere in the world. By the time Cordelia reached them, Agatha was cooing softly on Captain Hatmaker’s shoulder as he extracted a scroll from a tiny bottle on the bird’s leg.

Cordelia held her breath as her father unfurled it. He read it with a face like a closed door, then handed it silently to Cordelia. She recognized her aunt’s elegant handwriting, but the words had been written in a hurry and the scroll had been rolled up before the ink had time to dry. Everything in the smudged, urgent words spoke of desperation.

Flee with Cordelia and do not return! She is wanted for treason.

Is Sam with you? We are so worried! We love you always – Ariadne

Only then, in the grey dawn, with Aunt Ariadne’s familiar handwriting curled in her palm, did the chaos of yesterday begin to sink in.

Cordelia could not go home.

She was wanted for treason.

She would have to run for her life.