‘And you think they took it all the way upriver to Papua?’ He looked doubtful. ‘You said the submarine was 120 metres long.’

‘Where else could you hide something that big? This report states the body of Martin Heider was found in a seaplane float. And a Sentoku submarine carried three in a waterproof hangar!’

He nodded slowly, wanting, yet not quite able, to believe. ‘But surely after all these years it would have been found?’

‘You know what that country is like upriver, Father. You could hide twenty submarines up there and no one would ever know.’

She saw distaste in the set of his mouth. General Suyanto had loathed his years in Papua – the jungle, the insects and, most of all, the people, who were primitive savages.

‘The Sepik is vast,’ he agreed. ‘Do you have a specific location in mind, my darling?’

Sura spread out the topographical map upon which she had marked known German weapons finds, including the village where Wijaya had traded the old man for the dagger. Taking a pencil, she drew a circle around each of the four crosses.

‘These locations are less than seventy kilometres apart. Notice how every valley or tributary stems from the Hoosenbeck Gorge? Like branches from the same tree, the survivors fanned out looking for escape routes.’

‘My God, Sura, I think you’re right.’

‘Of greater interest is the Ford Mission.’ She pointed to its location. ‘Construction began in the late 1940s, and unlike similar organisations it is self-funded and has sister hospitals across the world. When I researched the founders, I discovered nothing. They seem to have no past, no explanation for their incredible resources.’

General Suyanto looked thoughtfully at the gleaming Knight’s Cross in his hand, then back to her.

‘An incredible story, Sura. But if you are right . . . How much gold was the submarine carrying?’

‘Four metric tonnes, Father.’

There was a loaded silence. General Wijaya Suyanto was one of Indonesia’s richest men, a billionaire, but the idea of 280 million US dollars’ worth of unclaimed gold and opium just sitting there for the taking was having the tantalising effect she had anticipated. To her surprise, he suddenly embraced her tightly.

‘You are truly my daughter. You have steel in you . . . like me.’

When he pulled away, eyes bright with emotion, she guessed it was as much grief for her brother, who would never amount to much, as it was pride in her achievement.

Seizing the moment, she launched into her case for leading the recovery.

‘We can do it under the guise of a documentary film. The Hoosenbeck Cave is world renowned and largely unexplored – no one would suspect a thing! Let me be a part of this, Father, let me see it through, you know I have experience in the field. Please, I beg you.’

His face went blank, and she knew she had crossed a line. Picking up the dossier, he deftly tucked it under his arm.