But he could do nothing to hold it back. The plane swatted him like a fly and an instant later the water smashed into the palazzo, washing the other men off the piazza.

The wave had completely swamped the dam, cracking the stonework, but as the flow diminished James saw that it was still standing.

It wasn’t over yet though.

When the ledge had hit the water it had sent out massive underwater shock waves unseen to James and the others and the stonework was fatally damaged. It would take next to nothing now to push the dam out and release the tremendous pressure of water behind it.

And there was something coming, something big.

A second wave had gone the opposite way up the lake, hitting the rocks at the far end, and, like water splashing about in a bathtub with nowhere to go, it was coming back.

It was smaller than the first wave but it was still powerful, and, as it crashed into the dam, the wall finally collapsed.

The massive force of 20 million gallons of water pushed the broken concrete out of its way in a mindless rush to escape. The plug had been pulled from the bath. The lake was draining and nothing could stop it now.

The aqueduct was obliterated, wiped out in an instant, sending stonework and masonry tumbling down into the valley. The palazzo didn’t stand a chance either; an unimaginable torrent of water and concrete and rock was sent hurtling into it. Columns and pillars were washed away like twigs. Whole buildings were ripped from their foundations and tossed down the mountainside. The parapets and walkways, the courtyards and all the fine squares and fountains were scrubbed into oblivion.

The people who were left inside had no chance. There was nowhere to run, even if they had had time or warning. The merciless water found its way into every hole and hiding place; nothing was spared. The few remaining roofs collapsed and the last of the walls buckled and broke apart. The tapestries and paintings, the statues and fine furniture, the silver ornaments and chandeliers were all utterly smashed to pieces and swept away.

After the water came the mud – an avalanche of sludge from the bottom of the lake and earth from the mountainside, an evil flow of dark, stinking slime. It forced its way through what was left of the windows and filled the rooms, so that soon there was nothing to see of Ugo’s palazzo and it was as if there had never been anything there.

‘What have you done?’ said James to Zoltan, who was staring at the lake that had quickly become a fast-flowing river.

‘I have drowned him,’ said Zoltan. ‘He was always worried about filth in his precious palazzo, now it will take a thousand years to clean.’