‘That’s your lot,’ said the guard, slamming the hatch shut.

Handing Cheng the rice, Yori lifted the water jug to Saburo’s lips while Jack supported his head. Saburo swallowed eagerly. He even managed a mouthful of rice. The combination was enough to return some colour to his cheeks.

‘Thank you,’ he said. His eyes flicked to Miyuki. ‘I owe you my life.’

‘That must be the first time a samurai has said that to a ninja!’ she replied with a fatigued grin.

As the five of them shared their meagre meal, Jack contemplated how they could break out. But their predicament appeared even more hopeless than in the pirate cage. The wooden grille was solid, the iron lock unbreakable, and the guards too far away to subdue. And once in Imabari, surrounded by a garrison of samurai, escape would be all but impossible.

‘I should have gone on alone,’ said Jack, looking regretfully round at his friends. ‘It’s my fault you’re in this mess.’

‘It was our choice,’ Miyuki reminded him. ‘We knew the risks.’

‘But you’d have been safe at home by now. Not trapped in this hell-hole.’

‘It’s better to be in chains with friends,’ said Yori, ‘than to be in a garden with strangers.’

Jack sighed. Yori always had an answer. ‘How did I ever deserve such good friends as –’

‘Listen!’ interrupted Miyuki, suddenly alert.

Jack and the others fell silent.

‘I thought I heard the sound of gunfire –’

The distinctive crack of a musket rang out, followed by panicked shouts and urgent commands. Above, the beat of the drum grew more insistent and Jack sensed a change in course.

‘What’s happening?’ asked Yori.

Jack was about to reply when the outer hull imploded. Timber shattered apart and a dragon’s face, twisted and scarred with hooked teeth and blood-red eyes, blasted into the bilge. The whole boat jarred under the impact. The two guards shrieked in terror as they were hurled from the steps. Jack and the others were thrown to the floor. By the time they found their feet, the dragon had disappeared and seawater gushed through the breach in the hull. The two guards scrambled up the steps as the bilge flooded.

‘Don’t leave us here!’ cried Cheng, pulling futilely at the grille.

The water level rose around them, while above the thunder of cannon and musket fire filled the air. The atake-bune shuddered again, keeling to one side.

Jack front-kicked the prison door. His leg jarred against the unyielding grille.

‘Let me try,’ said Miyuki. She targeted the lock. But that held firm too. She bent to examine it. ‘Maybe I could pick the lock. But I need something thin and pointed.’