‘You’re sure it was a torch?’
‘Positive. I was looking in the opposite direction, while you were communing with our dead lady. One look at that thing was enough for me. Then I saw the beam. It flashed out from somewhere on the left side of the cave.’
‘That’s where the other tunnel, the one from the House of the Vestals, should enter,’ Jack whispered. ‘But God knows how they got in.’
‘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.’