Yori, Cheng and Saburo were in a heap among the ropes and sailcloth. Miyuki had landed on the rice bales. It had just been Jack’s bad luck that his head hit the wooden water barrels. The gash didn’t feel too bad, but they were all scratched and bleeding from splinters of blasted timber.

‘What now?’ asked Cheng, looking in dismay at the destroyed steps.

Their way out was completely blocked by wreckage. Water swirled at their feet. The ship was sinking fast.

Jack glanced back at the hatch to the bilge. ‘We swim through the hole in the hull.’

‘But what about the dragon?’ asked Yori in horror.

‘We don’t have any other option,’ replied Jack, retrieving his katana as the light in the hold blazed brighter.

‘I’d rather take my chances with a dragon than this ship,’ said Miyuki. She pointed to the fire spreading through the wreckage towards the stocks of gunpowder in the bow.

Jack handed Yori the canvas bag, then pulled Saburo over to the hatch.

‘Take several slow deep breaths,’ he said, giving Saburo and Yori a crash course in ninja breathing techniques. ‘Clear your lungs completely, then suck in a large gulp of air and hold it.’

Saburo nodded. As soon as he’d taken his last big breath, Jack dragged him into the swirling water, the others following close behind. The blaze of the fire lit up the bilge and Jack easily spotted the hull’s gaping hole, black and jagged like the mouth of a shark.

Miyuki swam through first, Cheng right behind her. Yori was next. He briefly struggled with the canvas bag, which had air trapped inside and was acting like a float. As it cleared the hull, Yori shot up like a cork. Slowed by Saburo’s bulk, Jack was last and had to kick hard. With his arms round his friend’s chest, they made it through the hole. Then Saburo stopped with a jolt. Their eyes met in panic. Jack yanked on his friend, but to no avail.

Looking down, he saw Saburo’s breeches had snagged on the serrated edge of the hole. Jack tugged again. After the third wrench, the cloth finally tore free. But the mistake had cost them precious time and energy. Jack pumped his legs, praying for the surface before they ran out of breath. The darkness of night meant he couldn’t tell how much further there was to go. Then their heads cleared the water and Jack immediately wished they hadn’t. They’d surfaced in the middle of a ferocious sea battle. Captain Arashi’s fleet was being torn apart by a fire-breathing dragon, the flames from his burning ships flickering a hellish orange glow across the Seto Sea.