on the tier above. Several jets of water gushed out of the paving slabs, falling back into rectangular pools to run off into drainage holes. ‘This must be what makes the stream,’ suggested Kit.
‘Yeah, but what’s making them?’ said Nina. As well as the tinkle and splash of the fountains, there was still the other noise she had heard, considerably deeper. Beyond the palace, at the very rear of the cavern. ‘Back there.’ She started for the next flight of steps.
‘Where are you going?’ asked Osterhagen, surprised. ‘This is the Temple of the Sun! The Punchaco could be inside.’
‘There’s something I want to check,’ she said. ‘This cave was originally carved out by water. I want to find out why there isn’t still a river running through it.’
‘And I thought you married an archaeologist, not a hydrologist,’ Mac said to Eddie with a wry smile.
Zender edged nearer to the temple’s entrance. ‘We don’t need to wait for her, do we?’ Eddie shot him a cold look. ‘Ah, okay, okay. We can wait. Just for a minute.’
Nina scurried up the steps and forced herself to bypass the waiting temple and whatever riches it might contain to see what lay behind it. Her ears had not deceived her. A jet of white water, so much pressure behind it that it appeared almost solid, blasted out of a six-inch hole in the cave’s back wall into a deep pond, from where channels carved in the rock floor sent it downhill to different parts of the city. It was a primitive water main, a simple but effective piece of Inca engineering.
What was considerably less simple was the way the jet had been created. Surrounding the torrent was not natural rock but a wall, as precisely and solidly built as the towering defence at the cave mouth. It was almost like a plug set into the stone, roughly twelve feet across.
She hurried back to the square. The other team members had put down their gear and were waiting for her impatiently. ‘So, find anything interesting?’ asked Eddie.
‘Yes – I worked out how the Incas built this place,’ she said excitedly. ‘They must have dammed up the river before it went underground. Then they plugged up all but a little hole at the back of the cave so they’d have a water supply, and after that they built all of this, then demolished the dam. But since the river couldn’t flow freely down into the cave any more, it went over the top of it . . . and formed the waterfall. A whole city to hide their treasure, and it’s completely invisible from outside.’
Osterhagen was suitably impressed, taking in the ancient buildings surrounding them. ‘The Spanish never gave them enough credit for their engineering skills. That they could build a place like this is amazing.’
‘Their treasures were amazing too,’ said Zender impatiently, once again edging towards the temple’s entrance. ‘Dr Wilde, are you ready see what is inside? Or is their plumbing more interesting to you?’
Nina was tempted to make everyone wait by exploring the smaller buildings around the square, but decided that since Zender was only here for the glory of finding a big prize, the sooner he saw one the sooner he might leave. ‘All right,’ she faux-grumbled. ‘Let’s give baby his bottle.’ The group laughed, to Zender’s annoyance.
She and Osterhagen led the way to the darkened opening. While the limited space in the cave had forced the Incas to compress most of their architecture, the Temple of the Sun was, if anything, larger than its counterpart at Paititi. A short passage followed the curve of the outer wall before opening into a chamber.
Even before she reached it, Nina saw there was something unusual about the interior. Through the roof’s skeletal remains, the light in the passage had the same diffuse twilight cast as the rest of the cave. But the room ahead was different. Not brighter, but somehow warmer, almost like a dawn.
Osterhagen had seen it too. He quickened his pace. They entered the chamber . . .
And were bathed in golden light reflected off the object on its western wall.
‘Mein Gott!’ gasped Osterhagen, gasping. Nina was equally staggered.
They had found the Punchaco.
It dwarfed its copy from Paititi. That had been four feet in diameter; the golden disc before them now was nearer nine, and at least twice as thick as its counterpart. It stood almost floor to ceiling, mounted on the wall to face the trapezoidal eastern window. Unlike the smaller