The route march had been bad enough, but it had been punctuated by an experience that was etched in Fabius’ memory. On the Appian Way a few miles outside Rome, beyond the family tomb of the Scipiones, they had come across a line of wooden crucifixes being set up on the edge of the road. There had been a slave revolt in a travertine quarry to the east of the city, and the culprits were paying the penalty. They had seen the progression of death by crucifixion as they marched alongside, from those nearest the city who had been hoisted up first to the ones being set up that day: from the grey dangling corpses to the men still struggling for breath, their eyes wide open with fear, no longer with the strength in their arms to hold their chests up and prevent themselves from drowning in their own fluids, their legs and the post below streaked with faeces and urine and blood.
Gaius Paullus had turned away and retched, and the old centurion had pounced on him, pulling him up by the collar of his tunic and snarling into his face. ‘You can fight all the wars you want in the dioramas and sandpits of the academy. But you will never fight a real war unless you learn to love the sight of death. Breathe it all in. Learn to relish it. Otherwise you may as well go back and join the spotty youths in the Forum learning oratory and social niceties. Give me a girl like Julia in my legion any day over any of them.’ He had dragged Gaius Paullus along to the front of the line of crucifixes, stripped him of his load and spoken with the centurion commanding the execution party, who had gladly handed over the hammer and nails and ropes to the boys to carry on with the job. They had spent the next several hours hoisting and nailing prisoners to the crosses, enduring their writhing attempts to break free and the screams of pain as they knocked the foot-long spikes through their wrists and feet. Fabius had been sickened and knew that Scipio felt the same too, but there was nothing they could do to ease the agony for the prisoners; many were muscular giants captured in the Macedonian wars who should have been recruited as mercenaries to fight for Rome instead of being wasted in the quarries — another failing of Roman policy that Scipio Africanus had railed against but which for now they could do nothing to change.
At the end, Scipio and Gaius Paullus had stood in front of Petraeus while he addressed them. ‘I want you to become tribunes whom I would serve under,’ he had said. ‘That’s what Scipio Africanus told me to make of the students in the academy. Make them or break them, he said. And if I break you, you’ll feel the pain and the shame for all your lives. So you’d better learn what I’m telling you now. One day you are going to have to order men to be executed, some of them superb warriors like these slaves, some of them men you have fought alongside and loved like brothers. You will have to be able to do it in front of their comrades, without flinching, and without mercy. Now get back to the road, pick up those sacks of rocks and march. You’ve got thirty seconds or you’ll feel the lick of my whip.’
Fabius followed Scipio and Gaius Paullus down the rocky path into the crater, followed by Petraeus. Somewhere ahead of them in the smoke lay the Sibyl’s cave, and near that the crack in the earth that was said to lead to the underworld. As they reached the bottom of the slope they passed fissures stained yellow that reeked of sulphur, just like Ennius’ concoction in the academy. The base of the crater was an expanse of glassy rock as flat as a lake, wreathed in smoke that swirled up and obscured the sun, making the way ahead seem dark and forbidding. At the edge of the crater the rock bulged up in forms that looked like half-finished giants, borne of the earth but trapped in the rock before they could fully emerge. Polybius had told Fabius how he had been high up the volcano in Sicily and seen bulbous shapes like these as they were being formed, solidified from rivers of molten rock. He had said that the Phlegraean Fields truly were an entrance to the underworld, a place where the rock they stood on was a mere crust over the fiery chaos within, but that it was an entrance to Hades only inasmuch as those who lingered too long near the smoke or slipped into the molten streams were certain to die. Out of earshot of Petraeus he had said that those who came here were deluded, people whose desperation to know the future or to meet the shade of a loved one had tricked them into seeing visions, their minds fogged by the fumes and by the intoxicating leaf that the servants of the Sibyl burned on her fire; it was a leaf that Polybius himself knew was not some special gift of the gods but had been shipped from India by way of Alexandria, along with the drug known as lachryma papaveris, poppy tears. It was said that the priests of the Sibyl gave out these drugs freely to any of those who came to see her, and that those who brought gold were given especially large doses and were the ones who kept coming back for more, some of them wealthy aristocrats who had moved their homes from Rome to Neapolis and nearby Cumae just to be close to the source of the drugs that had begun to consume their minds.
Fabius caught sight of human forms huddled behind the rocks, staring at them. These were not aristocrats but were people who had fallen away from society, emaciated forms with faces and hands blackened by the smoke. It was said that they included a sect of Jews who believed that one day their god would come to them in this place; most, though, were escaped slaves and other fugitives from the law, those at the end of their tether who had come to spend their final days here before the fumes overcame them, hoping for some kind of salvation. One of them scurried up now, a filthy wretch clothed only in a loincloth, his eyes glazed over as if drunk, gesticulating wildly and pointing down a line of rocks laid across the floor of the crater. Scipio tossed him a coin and he scurried away, and then stopped and looked back at Petraeus for confirmation. He nodded, pointing forward, and they turned and made their way along the line of rocks, their feet crunching on the glassy surface of the crater. Fabius could feel the heat underneath and was glad for the thickness of his sandals, but Gaius Paullus was hopping and grimacing, the leather of his sandals smouldering. After what seemed an age they came to the other side of the crater and a tumble of rock that had fallen from the rim, in the middle of which was a jagged black hole the size of a temple entrance; in front was a hearth, tended by two black-robed forms who disappeared among the rocks as soon as they came close.
They had reached the cave of the Sibyl. They made their way up a well-worn path towards the hearth, the rocks smoothed by the countless supplicants who had clambered this way before. A few paces from the hearth they stopped, smelling the sweet odour that rose from the embers, and stared into the yawning blackness beyond. ‘They say she’s three hundred generations old,’ Gaius Paullus whispered, staring in awe. ‘They say she was old before Aeneas stood here, and is now so shrunken and wizened that she hangs in a little cage in the darkness, fed and tended by her priests like a pet monkey.’
‘Be careful what you say,’ Petraeus growled. ‘The god Apollo himself will hear you, and mete out his punishment.’ He turned to Scipio. ‘Her attendants have seen you, and she knows you are here. You must go forward alone into the cave.’
Scipio gave Fabius a wry look, took a deep breath and strode forward, walking around the hearth and disappearing out of sight into the blackness beyond. For a few minutes there was silence, and Fabius tensed, hating to see Scipio go out of his sight. And then a strange noise issued from the cave, indiscernible, like the muffled sound of a priest’s incantation in the back cella of a temple. A few moments later Scipio reappeared, stumbling towards them, his face flushed and running with sweat. He passed the hearth and then turned back to peer at the cave, breathing heavily.