The deck flooded and foamed with seawater and Jack was instantly drenched to the skin. The water cascaded away through the scuppers, and as he gasped for air, another tumultuous wave roared across the deck. This one, stronger than the first, swept Jack off his feet and he barely managed to grab hold of the ship’s rail to stop himself being washed overboard.

Jack recovered his footing as a jagged line of lightning scorched its way across the night sky and struck the main mast. For a brief moment, the entire ship was illuminated by a ghostly light. The three-masted ocean trader was in turmoil. Her crew were scattered across the decks like pieces of driftwood. High up on the yardarm, a group of sailors battled against the wind, attempting to furl the mainsail before the storm ripped it away, or worse, capsized the ship entirely.

On the quarterdeck, the Third Mate, a seven-foot giant of a man with a beard of fiery red hair, was wrestling with the wheel. Beside him was Captain Wallace, a stern figure who shouted commands at his crew, but all in vain; the wind whipped his words away before anyone could hear them.

The only other man on the quarterdeck was a tall and powerful sailor with dark brown hair tied back with a thin piece of cord. This man was Jack’s father, John Fletcher, the Pilot of the Alexandria, and his eyes were fixed on the horizon as if hoping to pierce the storm and seek out the safety of land beyond.

‘You lot!’ ordered the Bosun, pointing at Jack, Ginsel and two other crewmembers. ‘Get yourselves aloft and unfurl that topsail. Now!’

They immediately headed for the bow of the ship, but as they crossed the main deck to the foremast, a fireball plummeted out of nowhere – straight towards Jack.

‘Watch out!’ cried one of the sailors.

Jack, having already experienced several full-on attacks from enemy Portuguese warships during the voyage, instinctively ducked. He felt the rush of hot air and heard the deep howl as the fireball flew past and plunged into the deck. However, the impact was unlike the sound of a cannonball. It didn’t have the same fearsome crack of iron against wood. This was dull and lifeless as if it were a bale of broadcloth. With sickening horror, Jack’s eyes fell upon the object now at his feet.

It was no fireball.

It was the burning body of one of the crew, struck dead by the lightning.

Jack stood transfixed, sickness rising from the pit of his stomach. The dead man’s face was etched in agony and so disfigured by fire that Jack could not even recognize him.

‘Holy Mary, mother of God,’ exclaimed Ginsel, ‘even the Heavens are against us!’

But before he could utter another word, a wave crested the rail and swept the body out to sea.

‘Jack, stay with me!’ said Ginsel, seeing the shock rise in the boy’s face. He grabbed hold of Jack’s arm and tried to pull him towards the foremast.