Still the Nubian’s head was visible.

Above the noise and confusion, Romulus fancied that he could hear Ahmed’s voice shouting curses. It was the way he would always remember the pirate captain.

Dozens more arrows hissed down, ending the show.

He was very glad now that Mustafa had been left behind in Cana. With luck, his fate would be different to the rest of the crew. As always, Romulus wondered if the haruspex had known what would happen.

‘Let’s go,’ said Tarquinius.

With a start, Romulus came to his senses.

‘Before the trierarch sees us and sends some men ashore.’

‘Of course.’ He had been so wrapped up watching the one-sided battle that he had forgotten about the hostile reception they too would get from the Romans. After what they had witnessed, it was unlikely that any time would be granted to explain their status. Opting for discretion, the two friends crouched down and beat a path away from the trireme’s sleek shape. A gentle rocky slope led them up off the beach. Once over the crest, they were out of sight.

The warm sun beat down, drying them fast. But all they had with them was their clothes, chain mail and swords. Tarquinius also had his axe. There was one half-full water bag and no food. Neither had a bow, so hunting would be difficult.

We’re alive, thought Romulus grimly. That’s what counts. ‘How did you get away?’ he demanded.

‘I managed to grab one of Ahmed’s legs and knock him over.’

‘Without him splitting you in two?’

Tarquinius shrugged eloquently.

‘You could make it in the arena,’ laughed Romulus, clapping him on the shoulder.

The haruspex grimaced. ‘I’m getting too old for that,’ he said.

Romulus ignored his answer. It was not something he wanted to consider. A confident and assured young man now, he still relied on the other for psychological support.

‘Africa,’ announced Tarquinius with a grand gesture.

It was an amazing sight.

Before them, rich grassland rolled off to the west and north. A range of smooth, undulating hills filled the southern horizon. Small trees and scrubby bushes were dotted here and there. Irregularly shaped termite mounds projected upwards, fat red fingers of packed earth. The birdlife was richer here than anywhere Romulus had ever seen: as well as seabirds, there were honeyguides, orioles, kingfishers and countless other varieties. The animal life was no less varied. Several types of antelope, large and small, paced along, grazing as they went. Nearby, a group of magnificent horse-like creatures covered in wide black and white stripes was doing likewise, their tails flicking away flies. A herd of elephants stood around a waterhole, using their trunks to drink noisily and spray themselves with water. Elegant white birds walked along their backs, searching for parasites. If hit by a stream of water, they would indignantly fly away to alight upon another individual.

The peaceful scene was a stark contrast to the last occasion that they had seen elephants. Romulus did not want to dwell on that thought. ‘Look,’ he said in amazement, pointing at the striped animals.

‘Zebras,’ came the reply.

Tarquinius’ knowledge never failed to surprise Romulus. ‘How in the name of Hades do you know that?’

‘I saw one presented at a triumph for Pompey in Rome,’ replied Tarquinius.

‘And those?’ Romulus pointed at three strange-looking animals, which were feeding off the branches on the upper reaches of the trees. Their short coats were sandy-coloured with dark brown patches of different shades, and they had immensely long necks and legs. A short, upright mane ran up their necks and odd, stubby horns protruded from the tops of their heads.

‘Giraffes.’

‘Are they dangerous?’

‘Not really,’ laughed the haruspex. ‘They’re plant-eaters.’

Romulus flushed, embarrassed. ‘There must be lions, though.’ He had seen close up what the large cats could do to a man. Meeting one in the wild was not something he particularly wished to do.

‘Those we must look out for,’ agreed the haruspex. ‘As well as rhinos, buffaloes and leopards. It’s a pity that we have no spears.’

‘I’ve seen lions and leopards before, obviously,’ said Romulus, his eyes wide at the density of wildlife. ‘But not the others.’

This was an invitation for Tarquinius to begin one of his lessons. Naturally enough, he did not just mention the flora and fauna, but also the histories of Ethiopia and Egypt and the details of their civilizations and peoples.

When he had finished, Romulus felt more at home in this new and alien land, which had a much longer and richer past than his own. Like many others however, it was gradually falling under Rome’s influence. ‘How far is it to Alexandria?’

‘Many hundreds of miles.’

The scale of what faced them began to sink in. ‘Must we walk the whole way?’ he asked.

‘Possibly. It is unclear.’

‘Best make a start, eh?’ sighed Romulus.

They began to march north. Towards Egypt.

By the time they reached the waterhole, the elephants had gone. The shallow pool had been left muddied by the massive beasts, but there was nothing else on offer. Slaking their thirst and filling the leather water carrier, they moved on. Hunger was also gnawing at their bellies. In the circumstances though, that could wait. Putting a good distance between themselves and the trireme just off the coast was far more important than searching for food. While there was no sign of pursuit, both were careful to keep glancing in the direction from which they had come.

The morning passed without event, and Romulus began to relax. Keeping roughly parallel to the shore, they had covered perhaps eight or nine miles; they had escaped. Or so it seemed.

The young soldier felt little elation, however. Travelling on foot through Ethiopia and then Egypt, without proper weapons or enough companions, would be a Herculean task. While a similar distance, their journey down the Indus had been easier because it was by boat. This, on the other hand, felt akin to the odyssey that the Forgotten Legion had endured after Carrhae.

At least they had not been alone then.

By late afternoon, the pair had walked a further ten miles. Making their way to the sea again, they scanned the horizon for a long time. Nearly two decades younger, Romulus had the keener eyes. Happy that there was no sign of the trireme, he searched out a sheltered depression in the sand dunes which rolled back from the beach. Chopping the spiked lower branches from some nearby trees, the pair soon fashioned a high-sided, circular enclosure. It was large enough for them to lie down, and sleeping inside its protection would be safer than nothing at all.

They did not risk a fire. It was still quite warm and they had no food to cook. Any blaze would only attract unwanted attention anyway.

Tarquinius offered to take the first watch.

Gratefully accepting, Romulus fell asleep within moments. He dreamt of Rome.

When he awoke, thoroughly chilled, Romulus was unsurprised to find Tarquinius keeping vigil beside him. A faint light on the horizon hinted that daybreak was not far away. His friend had let him rest uninterrupted for the whole night. Feeling guilty, Romulus was about to say something, but held back. Facing east, the haruspex did not seem aware of his presence. Sitting perfectly still with his arms folded, Tarquinius resembled a well sculpted statue.

‘Forgive me, mighty Tinia,’ he whispered. ‘For what I have done.’

Romulus’ ears pricked up at the mention of the Etruscans’ most powerful god. As a Roman, he called him Jupiter.

There was a long pause, during which Tarquinius sat watching the myriad stars above gradually fade away. His lips moved in silent prayer.

Fascinated, Romulus lay still, doing his best not to shiver.

‘Great Mithras, accept my repentance,’ Tarquinius muttered. ‘I did what I thought was best. If mistakes have been made, then let me be punished as you see fit.’