‘But the old woman was mad,’ Akiko reminded him. ‘Why take her ravings seriously?’

‘She wasn’t mad – she was afraid!’ insisted Yori. ‘Afraid of the red wolf.’

Jack looked sidelong at Yori. ‘Are you suggesting that Sir Henry is the red wolf? Then perhaps you should be in Bedlam for thinking it! Sir Henry was a dear friend of my father’s. He’s our friend. He’s been helping us look for Jess. He’s offered me a job.’

‘Exactly,’ said Yori. ‘He needs you to sail back to the Japans to regain his lost fortune. I fear he would pretend to be your long-lost uncle if he thought it would persuade you. But I think he’s hiding something. A treasure far more precious than silver or gold.’

Yori led Jack and Akiko out into the moonlit courtyard. He pointed up at the window where Jack had thought he’d seen his sister’s face. ‘How many windows do you count on that floor?’

Jack looked. ‘Five,’ he replied.

‘Now come with me –’ With that, Yori scampered back inside, grabbing an oil lamp before heading up the central staircase.

Halfway up, they bumped into a servant coming down the other way, his face haggard and drawn in the sudden glow of the lamp. He carried an empty tray. ‘No guests are allowed on the upper floor,’ he muttered.

‘We just need to look for a window,’ said Yori, his reply perplexing the grim-faced servant as he pushed on past.

Jack and Akiko hurried after him, leaving the servant behind in the gloom. Reaching the top landing, Yori guided them round to the cobwebbed corridor. He stopped, the oil lamp spilling a wave of light across the floorboards to the attic room at the far end.

‘Count the windows again,’ he instructed Jack.

Starting at one end, Jack worked his way down the corridor and into the room. ‘One … two … three … four …’

But there was no fifth window. He re-counted. ‘Where’s the other window?’ he asked.

‘My point exactly,’ said Yori, crossing his arms in satisfaction. ‘Which means …’

‘There must be a priest hole!’ said Akiko breathlessly. Jack felt a sudden surge of shock.

Placing the oil lamp upon the writing table, they immediately set about searching the attic room. They tapped on the walls, listening for hollows. They checked the floor for loose boards, tested the ceiling for a trapdoor. But they found nothing.

‘Perhaps we counted wrong,’ suggested Akiko, her tone despondent.

Yori shook his head. ‘No, there are definitely five windows from the outside.’

Jack stood in the middle of the room and turned a full circle, his gaze exploring every nook and cranny. ‘The priest hole has to be somewhere,’ he said. Then he heard a faint scratching and he looked at the others. ‘Do you hear that?’

Akiko and Yori nodded, straining their ears to locate the sound.