A t five minutes to eleven the next morning Jack led Costas across the Piazza San Pietro in the Vatican, heading towards the Ufficio Scavi, the office of the archaeological excavations, on the south side of the basilica. They had flown in that morning from England on the IMU Embraer, arriving at Leonardo da Vinci airport away from public scrutiny, and Jack felt sure they were not being followed. The vast scale of the piazza and the surrounding colonnade seemed to dwarf the milling crowd of tourists and pilgrims, and they passed through as inconspicuously as they could. As they came closer to the Ufficio, Jack began to scan the faces around them, looking for some sign, some recognition. He had no idea what to expect. Then out of nowhere a young man was walking beside him, dressed casually in jeans and an open-necked shirt and wearing sunglasses. ‘Dr Howard?’ the man said. Jack looked at him, and nodded. ‘Please follow me.’ Jack glanced at Costas, and they followed the man as he strode ahead. After passing the Ufficio, he approached the Swiss Guard at the entrance to the Arco delle Campane, and flashed his identity card. ‘These are my two guests,’ he said in Italian. ‘A private tour.’ The guard nodded, and lifted up his automatic rifle to let them pass. They crossed a small piazza, then entered the south annex of the Grottoes beneath the Basilica. At the third room, the young man motioned for them to wait, and then walked over to a locked door. ‘We will not be disturbed,’ he said in English. ‘The Ufficio has closed this part of the Grottoes for more excavation work. Wait here.’ He produced a set of keys and opened the door, slipping through and leaving Jack and Costas alone, suddenly hemmed in by silence and the old walls.
‘Any idea what’s going on?’ Costas said quietly, his voice bunged up by his cold. ‘Any idea where we are?’
‘First question, your guess is as good as mine. Second, these walls are virtually all that’s left of the early basilica, the one built here by the emperor Constantine the Great after he’d converted to Christianity in the early fourth century. Before that, this was the site of a Roman circus, a racetrack. And where our guide has disappeared is the entrance to the necropolis, a street of rock-cut mausolea of the first century AD, discovered when archaeological excavations began here in the 1940s. Their big find was the tomb of St Peter, ahead of us under the high altar.’
The door swung open and the young man reappeared. He handed Jack and Costas each an unlit candle, and flicked a lighter over the wicks. ‘Where you see the candle on the floor, go right, but extinguish it and take it with you,’ he said quietly. ‘There are twelve steps down, then you’ll see another candle through another door. Pass through that door, and then close it behind you. I’ll wait for you here. Go.’
Costas looked pained. ‘We’re going underground again, Jack.’
‘It’s just your kind of thing. A city of the dead.’
‘Great.’
Jack paused, looked at the young man for a moment, decided not to speak, then nodded and walked towards the door, Costas following. They went through, and immediately the door was shut behind them. It was pitch dark except for the candles they were carrying and a faint glow somewhere ahead. It had been hot and dry outside, but the air was cool and damp as they descended, becoming musty. Jack led, carefully feeling his way down the steps until he reached a rough stone floor. They could see that the glow ahead of them was a candle on the floor. After reaching it Jack did as instructed, snuffing it out with his fingers and picking it up, then turning right and going down another flight of steps into a rock-cut chamber, evidently an ancient mausoleum long since cleared of its contents. At the bottom to the left was a stone door opened inwards in the rock, and through it they could see another distant pool of candlelight, just as before. They passed through, and Jack pushed the door back until it was shut, seamlessly fitting into the rock as if it were a secret entranceway.
‘Incredible,’ he murmured, looking around in the flickering candlelight, making out the niches and decorations on the walls. ‘It’s a catacomb. The mausolea we’ve just come through were originally above ground in the Roman period, a street of tombs. But this deeper part must always have been subterranean, cut into the living rock. The Vatican has never revealed this before.’
‘Makes you wonder what else they haven’t revealed,’ Costas murmured.
Jack stepped forward, sensing images on either side of him, inscriptions, paintings. He stopped at one, and held the candle forward. ‘Amazing,’ he whispered. ‘It’s intact. The catacombs are intact, the burials are still here.’
‘Just what I wanted to know,’ Costas moaned.
‘They’re sealed up, plastered over. Look, this inscription’s legible. In Pace.’ Jack faltered. ‘It’s early Christian, very early. It dates well before the time of Constantine the Great. A secret burial place, used when the Christians in Rome were outlawed, persecuted. This is a fantastic find. I can’t see why they haven’t made it public.’
‘Maybe something to do with this.’ Costas was ahead now, not far from the candle on the floor, and Jack cautiously followed. ‘It’s a raised area, covered with pottery tiles,’ Costas said. He made his way along the left side of the passageway and squatted down beside the candle.
‘It’s a tomb,’ Jack said quietly. ‘You sometimes get them in the floor of catacombs, as well as along the sides. Sometimes the floor tombs were the more important ones.’
‘Jack, I might be hallucinating. That deja vu thing you were on about under the Palatine Hill. Maybe a delayed nitrogen effect.’
‘What is it?’
‘That tile. Below the candle. There’s an inscription scratched on it. Either I’m seeing things, or it’s identical to a word we’ve come across before.’
Jack edged up behind Costas. There were decorative scratchings around the edge of the tile, like a wreath of vine tendrils. In the centre he saw what had sent a tremor through Costas. It was a name, unmistakable, a name they had seen scratched on pottery like this before, on an ancient shipwreck hundreds of miles away, lost for almost two millennia beneath the Mediterranean Sea. The name of a man, written in Latin.