‘If we could do it, someone else could.’
‘Massimo’s map showed entrances into the Cloaca in the Forum of Nerva and under the Colosseum,’ Jack said. ‘His guys were turned back by a flooded culvert, didn’t have the right equipment. Someone with the right gear could have found a way, but not one of his people. He’d have told us.’
‘Is this a coincidence?’
Jack paused, then stared into the darkness. ‘There’s something that’s been on my mind since yesterday. It wasn’t going to stop us coming to where we are now, and I was waiting to speak to her more, on the phone. You remember Elizabeth at Herculaneum, the superintendency official? My old friend?’
‘What’s she got to do with this?’
‘She caught up with me for a few moments yesterday in Herculaneum before we left the villa.’
‘Maria and I noticed.’
‘She was taking a big risk, with the guards around. Maurice had already warned us about how somebody seemed to be sitting on the superintendency people, keeping them from talking. She wanted to tell me something. About what we’re up against. An organization as deeply rooted in the history of Rome as you can imagine, that goes right back to the time of St Paul. An organization that knew the villa concealed a threat to their very existence, something they had hoped lost for ever in the eruption of AD 79. Elizabeth was whispering, and I didn’t have time to question her. She said they will do anything in their power to keep this threat at bay.’
‘You think we’re being followed?’
‘If it’s who I fear it is, they’ll have tentacles everywhere. And if they know we’re in here, they must assume we’re on to something. And if they somehow have an idea what it is we’re after, it’s a prize they’d die for.’
‘And kill for.’
Jack drew up behind Costas, and peered over his helmet. All he could make out was speckly green, with darker smudges at the end. ‘The only thing we can do is brazen it out. My guess is, it’s likely to be only one guy. The entrances from the forum and the Colosseum are pretty public. More than one might be too much of a risk, to get in unseen.’
‘Maybe the authorities turned a blind eye.’
‘Rome isn’t Naples,’ Jack said. ‘But you may be right. At the moment, whoever’s in that cave is going to be kicking themselves for having the torch on as they came out of the tunnel. I should imagine it was a pretty hairy ride, unless they had the kind of equipment we’ve got. And the longer we keep our lights off, the more likely they’ll assume we’ve rumbled them.’
‘You’re saying we should carry on as if we’ve seen nothing.’
‘Our intruder might think we’ve gone down a side passage, a dead end, come back up again. Let’s just switch on our lights, go forward. We’re going to have to have lights on anyway, to climb up that cavern to find the place beneath the shrine. They’re not going to have a go at us until we’ve found what we’re after.’
‘Okay. Lights on, sweeping them up from behind as if we’ve just come up from somewhere. I’m not armed, Jack.’
‘I’ve got the rock hammer in my right hand,’ Jack murmured. ‘If I hadn’t forced our security chief Ben to go on vacation, he’d have insisted that I carry the Beretta. There’s even a pocket for it in the e-suit. Lesson learned. Next time.’
‘Next time?’
They switched on their headlamps, then stood out in the passageway and began to make their way forward, passing the edge of the pool they had come up through. They knew they were being watched, but had no idea where from. After about ten metres they reached the end of the tunnel and the edge of the cave. They swept their beams around, and could see it was a huge natural cavern, extending at least twenty metres upwards. To the right was an ancient rock-cut stairway, winding up the natural contours of the cave, the tufa steps so heavily eroded they were sloping. About halfway up the cavern was a series of massive fractures and displacements in the rock, and they could see a continuation of the stairs far above that, near the ceiling, above a jagged precipice. Directly below that point on the floor of the cavern they could see an opening identical to the channel they had come through earlier, with rivulets just visible flowing into it. ‘That’s the other channel,’ Jack murmured, scanning the folds of rock around the entrance. ‘Can you see anything?’
‘Not yet.’
‘But thank God for Massimo and his rope. He was right. Looks as if we’re going rock-climbing.’
‘You are. I’m clambering round the base of the cavern, exploring for lost treasure, right? I might switch off my light, for better light contrast, you know, to see those secret chambers. Sometimes you might not see me.’
‘Be careful. This guy’s bound to be armed.’
‘He won’t shoot until he thinks we’ve found whatever it is we’re looking for.’
‘That’s the theory.’
‘Then don’t find it.’
‘I’ll tell you when to move on him,’ Jack said. ‘Loudly.’
Jack shifted the coil of rope off his shoulder in readiness and began to climb the steps. Costas was quickly lost to view among the folds of rock, and his beam disappeared. Jack hated the vulnerability, knowing that eyes were following his every move. Costas was no assassin, and was not the most inconspicuous of physiques. Jack stopped and looked up, ostentatiously. If they played their cards right, there was a chance. But some kind of showdown was inevitable. He steeled himself and carried on, focusing only on the challenge of the climb ahead. After thirty steps he reached the end, the point where the earthquake had pushed out a huge section of rock, creating a sheer face at least ten metres high. He inspected the rock, carefully judging the holds. It could be done. He clipped the rope to his harness, then unfastened the rebreather from his back, setting it down on the step behind him, unclipping the hoses from his helmet and lifting the visor. For the first time since the fetid blast from the drain an hour before he tasted the air. It was damp and warm, and he could hear water dripping all round him. The rainstorm Massimo had predicted must have started. He pulled himself on to the rock face. The tufa seemed friable, but he knew it was strong, volcanic stone that gave a good grip. He eased himself up, splayed on the rock, using his long limbs to find holds. About five metres up, he hammered in the first piton, the sound ringing through the cavern. He hammered another one in three metres higher. Another two metres and he was above the main precipice, with a ledge in front of him and then the stairs above, continuing into the rock face. To the right, he glimpsed a wide fissure that had walls covered with mosaic decoration, with embedded shells. It must be the fissure the archaeologists had found beneath the House of Augustus. He now knew with absolute certainty that the steps led up under the lost Palatine Shrine of Vesta, to the secret chamber they were seeking, only a few metres ahead.
He turned, hammered in a final piton just above the cliff edge, then clipped the rope to his harness and under his back, abseiling down the first few metres. He stopped and listened. The rivulet down the tunnel leading towards the forum had greatly intensified, and was now a torrent. The rainwater must have pushed the water reservoir from the spring over its threshold, and the tunnel was doing the job Claudius had designed it for. Jack paused, took a deep breath. This was it. He yelled out, as loudly as he could.
‘Costas, I’ve found it. I’m coming down.’
He bounced down another couple of metres, halfway down the cliff, the hammer in his left hand. Suddenly a grip like a vice held his left ankle, and he began spinning wildly. He looked down. A figure in a black wetsuit was staring up at him, wearing a close-fitting diving mask, legs wrapped around the rope just above the step. One hand held Jack’s ankle and the rope, the other held a silenced pistol, aimed at Jack’s head. ‘Give it to me,’ the man said coldly, in a thick Italian accent. Jack looked down, saying nothing. A bullet cracked past his face, followed by the thump of the silencer. It was a warning shot. Jack caught sight of something out of the corner of his eye, a shape. He swung, and aimed the hammer at the man’s head, a killer blow. But the arm holding his ankle was closer, and he brought the hammer down hard against the man’s wrist. There was an explosive sound as the bones snapped, and the pistol spun off into the cavern. Simultaneously Costas launched himself at the man’s legs, bringing him down with a huge crash. The man tried to get up, tripped, tumbled down and hit the channel below with a sickening crack, and then was gone, swept away down the tunnel in the torrent. Jack dropped down to help Costas, who had also removed his respirator and visor. ‘You okay?’
‘Fine,’ Costas panted. ‘Only wish you’d put that hammer in the little bastard’s forehead.’
‘I don’t think he’ll be troubling us any more,’ Jack said.
Costas wiped some blood off his mouth and looked down. ‘Well and truly flushed out.’ He looked back up the cliff face. ‘Right. Hook me up. That’s done it for me. The sooner we get what we’ve come for and get out of here, the better.’
Twenty minutes later they were in a narrow space above the final flight of rock-cut stairs. Jack squeezed himself as far up the crack as he could go, his arms raised above him into a hollowed-out chamber. He could feel nothing. He wriggled further, but it was no use. His head was jammed sideways against the top of the crack, and all he could see was the side of the jagged fissure inches from his face. He felt blindly with his hands, but there was only empty space. He arched his back, pushing hard, and felt himself move fractionally forward, an inch or two. Suddenly his fingers met resistance. Wet rock, smoothed down, different from the irregular rock of the fissure. He parted his hands and felt around. It was a circular chamber, about two feet wide, sunk into the rock. He felt down as far as he could reach, and touched the base of the chamber. He traced his fingers slowly around the edge. Nothing.
It was empty.
Jack slumped slightly, and peered down at Costas’ face, just visible below his feet. ‘I can feel the chamber.’ His voice sounded peculiar, resonating in the chamber but then deadened in the fissure. ‘It’s a cylindrical hole bored into the rock. I can feel all round the base. There’s nothing inside.’
‘Try the middle.’ Costas’ voice sounded distant, muffled. ‘Maybe there’s another smaller chamber sunk below it.’
Jack shifted as far as he could to the right. He slowly drew his left hand across the bottom of the chamber. It was wet, slimy, with small ridges and furrows, as if it had been left roughly finished. He reached the other side. Suddenly he pulled his hand back again. There was a regularity to the furrows. He felt around, his eyes shut, tracing the marks, trying to read what he was feeling. There was no doubt about it. ‘You’re right,’ he said excitedly. ‘I can feel the outline of another circle, an inner circle on the floor of the chamber. I think it’s a lid, a stone lid. I can feel markings on it.’
‘Is there a handle?’ Costas said.
‘Nothing. It’s flat across the top. I’ve no idea how we’re going to open this.’
‘And those markings?’
‘I can count twenty so far,’ Jack said. ‘Wait.’ He flinched in pain as he jammed his elbow against the crack, trying to feel every part of the lid surface. He worked his hand round. ‘No, twenty-three. They’re in a circle, around the edge of the lid. They’re letters, raised letters carved on little blocks, set slightly into the stone surface. It’s curious. I can actually press them down slightly.’
‘Can you read them?’
Jack traced his fingers around the letters. He suddenly realized what they were. ‘It’s the Latin alphabet, the alphabet of the later Roman Republic and the early empire. Twenty-three letters. Alpha to zeta.’
‘Jack, I think what you’ve got there is a combination lock, Roman style.’
‘Huh?’
‘We studied these things at MIT. Ancient technology. If there isn’t a handle, the lid must have some kind of spring opener, set underneath to push it up. My guess is a bronze spring, set around the edge of the inner chamber. The letters must be a combination lock, probably attached to stone or metal pivots that secure the lid into the rock. The combination might be adjustable, allowing the person using it to reset it each time with a new code. Press the right combination, and bingo, the lid springs up.’
‘Twenty-three letters,’ Jack murmured. ‘And no way of knowing how many we need to press. I don’t even want to begin to calculate the number of possibilities.’
‘Let’s start with the obvious,’ Costas said. ‘It was Pliny the Elder who put the scroll here, right? What was his full name?’
Jack thought for a moment. ‘Caius Plinius Secundus.’
‘Okay. Punch in the initials.’
Jack pictured the Latin alphabet in his mind’s eye, and traced his finger around the circle until he came to each letter.
C, P, S
. He pressed them in the correct order, and they depressed very slightly, but no more. He tried again, then in a different order. Still nothing.
‘No good,’ he said, his teeth gritted.
‘Then your guess is as good as mine,’ Costas said. ‘You may as well try random combinations. We shouldn’t be here for more than a week. We really need to get going, Jack. Our friend might not be the only one. We don’t know.’
‘Wait.’ Jack’s mind was racing. ‘You might have the right idea. Let’s think about this. Pliny gets the document from Claudius. He promises to hide it away. Pliny keeps his promises, and never puts anything off. He’s got too much else to do, managing the naval base, writing his books. He takes his fast galley up to Rome that night, 23 August AD 79, right up the Tiber, comes straight here to the Admiral’s safety deposit box, returns that same night to Misenum on the Bay of Naples, just in time for the eruption. Whose name is fresh in his mind?’
‘You mean Jesus? The Nazarene?’
‘Not enough there for a code, and it might be too obvious. No. I mean Claudius himself. His name before he became emperor. Tiberius Claudius Drusus Nero Germanicus.’ Jack shut his eyes again, moved his hand over the letters and pressed them in.
T, C, D, N, G
. Nothing. He repeated it. Again nothing. He exhaled forcibly. ‘No good.’