There was a feeling of peace and calm. The air smelt clean. On a day like this only good things could happen.

Then there was a deep boom and a flock of white doves flew up into the sky like a spray of litter.

The boom was followed by distant bangs, and the sound of panicked shouting.

It had started.

James moved quickly. He lifted the pickaxe and swung it as hard as he could at the centre of the floor. He paused, listening for Amy’s warning yell, but all he could hear was the growing sound of confusion and gunfire in the palazzo. He swung again and a crack appeared. Again he swung and again until a chunk of concrete gave way and dropped into the room below. Two more swings and he’d opened up a sizeable hole. He saw Amy looking up at him, with dust in her hair.

‘Are you all right?’ he said.

‘I think so.’

‘Any sign of your guards?’

‘No.’

‘Good. Stand back, and keep as close to the wall as you can.’

James lifted the pickaxe and carried on swinging.

In a few minutes he had a hole wide enough to fit into. Then suddenly there was a great crash as half the floor collapsed. He lowered the rope to Amy.

‘Grab hold of this,’ he shouted and braced himself. Amy climbed and he pulled and eventually she slithered up through the hole into the room. She was covered in chalky powder and her eyes were glassy with fear. She gave James a big hug and he was glad of the human contact.

‘We’ve got to get out of here,’ he said. ‘Can you swim?’

‘Yes.’

‘Come on then, let’s go.’

James was about to go to the window when he heard a key rattling in the lock. Thinking quickly he gave one end of the rope to Amy and pointed to the other side of the door. Luckily she seemed to understand what he meant and they took up their positions, flattened against the wall.

The door flew open and a guard rushed in. They yanked the rope and he tripped, falling face forward into the hole, smacking his head on the edge as he went down.

‘Let’s get out of here,’ said James, and Amy didn’t argue.

They ran through the door that the guard had unlocked and found themselves in a dark, twisting corridor that eventually led outside into a sunny square.

There was panic and confusion everywhere. People were running in all directions, yelling. The servants were trying to get away and the guards were trying to get to the fighting, although they didn’t seem too sure of which direction they were being attacked from. James and Amy passed unnoticed through the chaos, working their way up through the palazzo towards the aqueduct.

After a couple of dead ends, James spotted the equestrian statue.

‘This way,’ he said, running along a walkway.