'Most of what you can discern is on the inner surface. Mark the dog star, Sirius. This is the large bear, Ursa Major.'

He peered at the points indicated, his book learning beginning to make real sense. The haruspex spoke at length about interpretations to be made from the colour, shape and consistency of the glistening organ. To Tarquinius' astonishment, Olenus brought up many details of his childhood that he could not possibly have known. The old man recounted Tarquinius' whole life, pausing every so often to allow his pupil time to interpret.

'The gall bladder.' He poked a tear-shaped sac protruding from the liver's centre. 'Represents what is hidden. Sometimes it can be read, sometimes not.'

Tarquinius touched the warm bag of fluid. 'Is much visible?' It was the hardest part of the divination to perform and he had never made any sense from the livers he had practised on.

Olenus was silent for a few moments.

Heart racing, Tarquinius studied the haruspex' face. There was something there. He could feel it.

'I see you join the army and travel to Asia Minor. I see many battles.'

'When?'

'Soon.'

Tarquinius knew that the eastern region of Asia Minor had been a hotbed of rebellion and conflict for some time. A generation before, Sulla had soundly defeated Mithridates, the warlike king of Pontus, but his concerns about the uncertain political situation in Rome had made him pull back without delivering the final blow. Mithridates had bided his time, until four years previously when his armies had surged into Pergamum, the Roman province in the area. Lucullus, the general sent by the Senate, had achieved impressive victories since, but the war was still going on.

Amused by the idea of fighting for the Romans, Tarquinius felt a sharp nudge. 'Pay attention!' barked the old man. 'Years of travelling, learning. But eventually Rome draws you back. A desire for revenge.'

'On whom?'

'A fight.' Olenus seemed to be in a trance. 'Someone of high rank is killed.'

'By me?' Tarquinius asked suspiciously. 'Why?'

The answer came to him.

'A voyage to Lydia by ship. There two gladiators become your friends. Both brave men. You will become a teacher, like me.'

The dagger tip swept from gall bladder to other points on the purple organ. The haruspex began muttering rapidly. Tarquinius found he could only pick out occasional words. He gazed at the liver, delighted that he could also see what Olenus was reading.

'A huge battle, which the Romans lose. Slavery. A long march into the east. The Lion of Macedon's path.'

Tarquinius smiled. Some said the Rasenna – the name the Etruscans called themselves – had come from further afield than Lydia. Perhaps he would learn something from the travels of Alexander.

'Margiana. A journey by river, then another by sea.' Olenus' expression grew troubled. 'Egypt? The mother of terror?'

'What is it?' Tarquinius tried to see what had alarmed his mentor.

'Nothing! I saw nothing.' The old man threw the lamb's liver down, taking a few steps backwards. 'I must be mistaken.'

Tarquinius stepped closer. The gall bladder had begun to leak a thin, greenish fluid onto the stone. Concentrating hard, he still found it difficult to interpret. Then his vision cleared. 'Egypt! The city of Alexander!'

'It is not.' Sounding angry and scared, Olenus pushed Tarquinius out of the way, turning the liver over so he could no longer see the underside. 'Time to see the sword of Tarquin.'

'Why? What have you seen?'

'Many things, Arun.' Olenus' eyes darkened. 'It is sometimes best not to say.'

'I have a right to know my own fate.' Tarquinius squared his shoulders. 'You saw yours.'

Olenus' face sagged. 'True enough.' He gestured with the blade. 'Look, then.'

Tarquinius held back, considering the options. He had learned how to read the liver thoroughly at last and would have plenty of opportunity to do so in years to come. His mentor had seen a fascinating future. But there had also been something quite unexpected.

Tarquinius had little desire to know everything that would happen to him.

'It will be revealed in time,' he said calmly.

Relieved, Olenus picked up the lituus and pointed back into the cave. 'We must find the sword. You are ready.' He patted Tarquinius affectionately.

Before they entered the dark interior, Olenus produced a handful of rushes, their ends dipped in wax. Using two pieces of flint, he lit a pair of torches. 'Take one.'

Making sure the burning wax did not run down his arm, Tarquinius followed the old man inside. The cave opened out as they went deeper, running straight into the rock for a good three hundred paces. The air was cool but dry.

He jumped as the torchlight revealed richly coloured paintings on the walls.

'This place has been sacred for many centuries.' Olenus pointed out the figure of a haruspex, obvious with his blunt-peaked hat and lituus. 'See how he holds the liver in his left hand and looks at the sky?'

'This must be Tinia.' Tarquinius bowed before an unusually large image, depicting a figure identical to the little terracotta statue kept on a shrine in Olenus' hut. The deity had staring, almond-shaped eyes and a straight nose, framed by tight curls and a short, pointed beard.

'The Romans call him Jupiter.'

Olenus scowled. 'They even took our most important god.'

The soothsayer beckoned Tarquinius deeper into the gloom, past more paintings of ancient rituals and feasts. Musicians played lyres and the auletos, the Etruscan double flute. Graceful dark women in colourful, flowing robes danced with fat, naked men as satyrs leered from nearby rocks. Mighty Etruscan warriors in full armour guarded one scene, and a naked male figure with wings and a lion's head hovered overhead. The intensity in the beast's eyes stirred something deep in him.

'Gods above!' Tarquinius swelled with pride, imagining Etruria in its glory days. 'These are better than anything in Caelius' house!'

'Or most villas in Rome.' The old man came to a halt by the entrance to a side chamber. Raising his torch, Olenus moved a few steps towards a large shape on the floor.

'What is it?'

The haruspex did not answer and Tarquinius dragged his gaze away from the murals. It was a moment before he took in the ornate bronze panels, metal-clad wheels and square fighting platform of an Etruscan battle chariot. He gasped.

'Achilles is receiving his armour from Thetis, his mother.' Olenus pointed at the depiction on the chariot's front section.

Chunks of ivory, amber and semiprecious stones had been carved to colour the scene. The central tongue and twin neckpieces for horses were similarly covered with tiny pictures of the gods. Even the nine-spoked wheels had sacred symbols etched on their sides.

Full of awe, Tarquinius ran his fingers over the wood and bronze, soaking up the details and dislodging a thick layer of dust. 'How old is it?'

'It belonged to Priscus, the last to call himself king of the Etruscans,' replied Olenus solemnly. 'And it was over three centuries ago that he ruled Falerii. They say he led more than a hundred of these into battle.'

The young man shivered with delight, picturing the impressive sight of the king dressed in plates of bronze armour, standing with a drawn bow behind his charioteer. Following in a vast wedge would have been the rest of the chariots and then the massed ranks of infantry.

'The testudo formations could withstand their charges though,' sighed Olenus. 'Simply closed up and weathered the arrow storms.'

Tarquinius nodded sadly, familiar with the story of Falerii's end. Somehow it had endured for more than seventy years after Rome had crushed all of its neighbours. When it did arrive, the fate of Falerii – last of the proud city states – had been decided in a few short hours. The Roman legionaries had massacred the less disciplined Etruscan foot soldiers and cut down many of the charioteers with well-thrown javelins. His army in tatters, the mortally wounded Priscus had fled the field. 'Is he buried in here?' he asked, staring into the corners.