‘As only an ignorant emperor could,’ Iolanthe said. ‘He hated the educational advantage they had. For many centuries the Vestal priestesses occupied a very powerful position in Roman society, chiefly because they hoarded in their temple a vast repository of ancient astronomical knowledge, most of it sourced from Egypt. It was easy to dazzle an uneducated populace by predicting an eclipse that you knew was coming. To the regular folk of Rome, the Vestals were almost magical in their wisdom and the Vestals happily encouraged this.’

Nobody said, ‘Didn’t the Vestals tend to some kind of eternal flame?’

‘Yes,’ Iolanthe said. ‘Inside their temple, the Vestals famously kept alight the sacred flame of Rome. They had convinced the people of Rome that this flame embodied Rome’s very essence, its lifeblood, its soul. If the flame went out, Rome would collapse into ruin.

‘It was very clever. Not only had they made themselves appear magical by virtue of their advanced knowledge, with the sacred flame they made themselves indispensable to the continued existence of the entire Roman nation.

‘Thus the Roman people went to great lengths to keep the Vestals happy. Their virtue was protected. Anyone who deflowered, raped or killed a Vestal forfeited their life. It became a great honour for someone’s daughter to be accepted into the order. Naturally, the Vestals had enemies, among them Domitian and the rising Christian movement which for some reason didn’t like women with brains.

‘When Rome fell to the Vandals in 455 C.E., the Vestals fled their temple and extinguished the sacred flame. Once that flame went out, Rome was no more, which actually only furthered their mythology.’

‘Do they exist today?’ Nobody said.

‘Of course they do,’ Iolanthe said. ‘Just like the Cult of Amon-Ra became the modern-day Catholic Church, so too did the Vestal order transform. It just changed its name and base of operations every few centuries. Why, you’ve even met two modern Vestals: Sister Lynda and Dr Tracy Smith.’

‘Oh, no way . . .’ Nobody said, finally getting it. ‘The nuns from Moscow.’

‘Correct,’ Iolanthe said. ‘The current name of the Vestal priestesses is the Order of Serene Maidens at Novodevichy Convent.’

‘Here!’ Bertie shouted suddenly, making both Iolanthe and Nobody spin. ‘Here it is!’

He was looking at a line on the second scroll.

‘What have you got?’ Iolanthe asked.

Bertie said, ‘It says here:

“The location of the Orphean Bell is inscribed on the Crown of Priam, the most honest man of his time, guardian of the mighty vault at Ilium, trusted keeper of the treasures of the four kings of old.”’

Nobody cocked his head. ‘Priam? Ilium? Even I know what Ilium is. It’s Troy, the site of the Trojan War. Priam was the king of Troy.’

Iolanthe frowned in thought.

She gave Bertie a concerned look. ‘The Crown of Priam used to be kept by the King of Land at his hunting retreat on the Welsh coast.’