James’s head was throbbing and he thought that if he didn’t get out of the sun soon it would explode. He was just wondering what to do when one of the boys came over from the railway car.

‘Mauro!’ he cried.

‘Stefano! Che cosa fai qui?’

Mauro grinned from ear to ear and the two of them gabbled excitedly to each other, interspersed with much Italian hugging and slapping.

It turned out that Stefano was from Mauro’s village and he worked here in Ugo’s kitchens. He seemed to know the guard and eventually managed to get through to him that his friends had an important message to deliver to Victor Delacroix up at the palazzo.

The guard shuffled into his hut and came out after a while with a sheaf of densely typewritten papers. He leafed through them, turning from one page to the next agonisingly slowly, but at last a vague glimmer of light came into his eyes.

‘Victor Delacroix?’ he said, and James nodded.

‘Bene.’

He nonchalantly waved James and Mauro on to the railway car and explained the situation to another guard who sat inside, sheltering from the sun.

As he climbed aboard, James studied the carriage. It was attached to a thick steel cable and sat on a sloping, wedge-shaped base so that it would remain level as it made its way up the dizzyingly steep angle of the track.

The guard pulled some levers and James heard a swooshing, gurgling sound from below. He looked out to see that a tank of water underneath the carriage had been emptied into a concrete channel. He assumed that the train must operate on some sort of counterweight system.

With a jerk, they moved forward and began to climb up the mountainside.

James sat down on a plush, velvet seat next to Mauro. He wondered if this ornate railway had once been part of Ugo’s mining operation. It certainly didn’t look like a mining carriage now, though: the seats were padded velvet and the walls were covered in carved wood and gold leaf.

Halfway up they passed a second car coming down, packed with more baskets and palazzo workers, then they crossed over a bridge that spanned a deep black chasm in the ground. On the other side of the bridge they passed into a tunnel that had been cut into a great jutting outcrop of rock and as they emerged back out into sunlight they came to the first of the palazzo buildings. James looked up at high, sheer walls dotted with small windows and got the occasional glimpse inside as they climbed past them. The higher they got the finer the buildings became, and James saw lookout towers, large statues and raised walkways. Finally, nearly ten minutes after setting off, they came to rest at the top of the palazzo where a wide, handsome piazza had been built.