‘Got you,’ Costas said. ‘Pliny the Elder. Admiral at Misenum.’
Jack nodded. ‘Pliny would have known this place well. Augustus also built a new shrine to Vesta at this spot, probably meant to supplant the one in the forum.’
‘Right under his bedroom window,’ Costas said. ‘Talk about control.’
‘The Vestal Virgins seem to have resisted the idea of moving their sacred shrine, and continued to patronize the old one. And here’s the really fascinating thing, the reason we’re here. The shrine to Vesta in the forum contained an adytum, an inner sanctum, a hidden place where various sacred items were stored. Its contents were pretty mystical, sacred objects to do with the foundation of Rome. The fascinum, the erect phallus that averted evil, the pignora imperii, mysterious pledges for the eternal duration of Rome, the palladium, a statue of the goddess Pallas Athena supposedly brought by Aeneas from Troy. Only the Vestals and the Pontifex Maximus were ever allowed in, and these items were never shown in public.’
‘A secret chamber,’ Costas mused. ‘So if Augustus was planning this new shrine as a replica of the old, he would have had a chamber built into this one too?’
‘My thinking exactly.’
‘But if the sacred items remained in the forum shrine, this new one would have been empty.’
‘Or not quite empty.’
‘Are you saying what I think you’re saying?’
Jack opened his bag and pulled out a clipboard with a blown-up photograph of a Roman coin on the front. ‘This is the only known depiction of the new shrine, the Palatine Shrine of Vesta. It’s from a coin of the emperor Tiberius, of AD 22 or 23. You can see a circular colonnaded building very similar to the old shrine in the forum, clearly emulating it. The circular shape was meant to copy the hut form of the earliest Roman dwelling, the so-called House of Romulus, which was carefully preserved as a sacred antiquity on the other side of the House of Augustus. You can still see the postholes in the rock. What else can you see on that coin?’
Costas took the clipboard. ‘Well, the letters S and C above the shrine. Senatus Consultum. Even I know that. And the shrine’s got a column on either side, a plinth with a statue on it. They’re animals, possibly horses.’ He paused, then spoke excitedly. ‘I’ve got you. Not horses. Bulls.’
‘That’s what clinches it,’ Jack said excitedly. ‘We know from the ancient sources that two statues stood in front of the Palatine Shrine of Vesta. Statues of sacrificial animals, sacred to the rites of the Vestals. Both statues were originally Greek, by the famous sculptor Myron of the fifth century BC. Statues of cows.’
‘Of course.’
‘Remember our clue,’ Jack enthused. ‘ Subduo sacra bos. Beneath the sacred cows. These two statues were a unique pair. There was nothing else like them in Rome. This can only be what Pliny meant. He hid the scroll here, in the empty chamber under the Palatine Shrine of Vesta.’
‘Where exactly?’ Costas had taken out a GPS receiver and was looking round, eyeing the featureless ground and dusty walls dubiously.
‘My best guess is where we are now, give or take ten metres either way,’ Jack said. ‘All trace of the shrine is gone, but it seems clear that it would have been on this side of the temple portico, right beside Augustus’ house.’
‘Ground-penetrating radar?’
‘Too much else going on here. The place is honeycombed, building built on building. Even the bedrock’s full of cracks and fissures.’
‘So what do we do now? Get a shovel?’
‘We’ll never find it that way. At least not without a lot of money, a lot of bureaucracy, and about a year for the permit to come through. No, we’re not going to dig down.’
‘So what can we do?’
‘We might be able to go up.’
‘Huh?’
Jack took back the clipboard, closed his bag and jumped to his feet. He checked his watch. ‘I’ll explain on the way. Come on.’
Twenty minutes later they stood on a terrace on the north side of the Roman Forum archaeological precinct, with a magnificent view of the heart of ancient Rome stretching out in front of them and the vast bulk of the Colosseum in the background. ‘This is the best place to get a sense of the topography, ’ Jack said. ‘At its height this was a huge conglomeration of buildings, temples, law courts, monuments, all crowding in on each other. Strip all that away and you can see how the forum was built in a valley, with the Palatine Hill on the west side. Now look to our right, below the north slope of the Palatine, and see how the valley sweeps round towards the river Tiber. Where we’re standing now is the Capitoline Hill, the apex of ancient Rome, the place where the triumphal processions reached their climax. Just to the right of us is the Tarpeian Rock, where criminals were flung to their deaths over a precipice.’
‘The miscreant Vestals?’
‘Traditionally their place of execution is thought to have been outside the city walls, but Pliny the Younger only mentions an underground chamber. It could have been close by.’
‘So tell me about underground Rome,’ Costas said. ‘Not that I want to go there. Three thousand years of accumulated sludge.’
Jack grinned, opened his bag and pulled out the clipboard again, folding back the sheet with the image of the coin to reveal a copy of an old engraving, the word ROMA in large letters at the top. The centre of the map showed topographical features, valleys, hills and watercourses, and around the edge were building plans. ‘This is my favourite map of Rome,’ he said. ‘Drawn by Giovanni Battista Piranesi in the eighteenth century, about the same time that the Villa of the Papyri at Herculaneum was first being explored. The fragmentary plans of buildings around the edge are drawings of chunks of the famous Marble Plan, a huge mural originally displayed in Vespasian’s Temple of Peace. Only about ten per cent of the Marble Plan survives, in fragments like this.’ To Jack, Piranesi’s map was like a metaphor for knowledge of ancient Rome, like an incomplete jigsaw puzzle with some areas known in great detail, others hardly at all, even building layouts recorded exactly but their actual location lost to history.
‘It shows the topography very clearly,’ Costas said.
‘That’s why I love it,’ Jack replied. ‘Piranesi kept the pieces of the jigsaw to the edges, swept aside the buildings, and focused on the hills and valleys. That’s what I wanted you to see.’ He angled the map so it had the same orientation as the view in front of them, and traced his finger over the centre. ‘In prehistoric times, when Aeneas supposedly arrived here, the forum area was a marshy valley on the edge of a flood plain. As the first settlements spread down the slopes of the hills into the wetland, the stream was canalized and eventually covered over. It became the Cloaca Maxima, the Great Drain, extending beyond where you can see the Colosseum now, then right under the forum, then sweeping round in front of us and flowing into the Tiber. There were tributaries, streams running into it, as well as artificial underground constructions, the channels of aqueducts. It’s all still there, a vast underground labyrinth, and only a fraction of it has ever been explored.’
‘Where’s the nearest access point?’
‘We’re heading towards it now. Follow me.’ Jack led Costas off the terrace and down into Via di San Teodoro, the ruins on the Palatine rearing up to the left and the buildings of the medieval city to the right. They veered right again into a narrow street which opened out into a V-shaped courtyard, with traffic thundering beyond. In the foreground was a massive squat ruin, a four-way arch with thick piers at each corner. ‘The Arch of Janus,’ Jack said. ‘Not the most glorious of Rome’s ruins, pretty well denuded of anything interesting. But it stands astride the Cloaca Maxima. The place where the drain disgorges into the river is only about two hundred metres away, beyond the main road.’ They went through an opening in the iron railing surrounding the arch and walked under the bleached stone. On the forecourt on the other side a van was drawn up and two clusters of diving equipment were laid out on the cobbles, with two IMU technicians running checks on one of the closed-circuit rebreathers.