Here and there, tell-tale yellow glowing patches appeared. They spread fast, reaching the masts within a matter of moments. Fabiola could not help but admire Caesar’s ingenuity.

Wails of dismay rose from the watching Egyptian soldiers. Their fleet was going to burn.

And then the legionaries hit them.

Reaching Alexandria had not proved difficult. After a long march in late-afternoon sunshine, the two friends had arrived at the southern outer walls. Gaining entry was similarly easy. Plenty of guards were on duty, bored-looking Egyptians in Roman-style mail and helmets, but they showed little interest in a pair of dusty travellers. Closing the Gate of the Sun at sundown was of more concern. Although keen to find out what was going on, Romulus and Tarquinius had not asked any questions of the sentries. It was not worth the potential problems they might encounter if their own armour and weapons were discovered. They would have to find out what they could from ordinary citizens.

But there had been little activity within the city. In fact, it was almost deserted. Even the Argeus, the main street which ran north to south, was virtually empty. A few people scuttled here and there between the obelisks, fountains and palm trees on its central parade, but the usual stalls selling food, drink, pottery and metalwork were abandoned, their wooden surfaces bare. Even the huge temples were vacant of worshippers.

It looked as if Tarquinius’ predictions were right: there had been fighting.

Their suspicions were raised further by the sight of Egyptian troops assembling outside what looked like a large barracks. Aware that they could be regarded as enemies, the pair ducked out of sight into an alleyway. More soldiers filled the next street as well. Using Hiero’s directions and the position of the sunlight, they worked their way through the rectangular grid of thoroughfares towards the centre. Romulus’ uneasiness grew steadily as the distance from the southern gate increased. But they could find no one to talk to. And Tarquinius was like a man driven: his expression eager, his pace fast.

By the time darkness fell, they had passed the tree-covered Paneium, a man-made hill dedicated to the god Pan, and the immense temple to Serapis, the god invented by the Ptolemies. Romulus was awestruck by Alexandria’s architecture and layout. Unlike Rome, which had only two streets wider than an ordinary ox-cart, this city had been built on a grand scale to an imaginative master plan. Rather than single impressive buildings or shrines dotted here and there, whole avenues of them were laid out. Everywhere there were grand squares, splashing fountains and well-designed gardens. Amazed by the Argeus, Romulus was bowled over by the Canopic Way, the main avenue which ran east to west straight across the city. At its intersection with the Argeus, he was able to appreciate its extraordinary length thanks to Alexandria’s flat terrain. The junction itself was dominated by a magnificent square filled with an obelisk and a huge fountain, which was decorated with marvellous statues of water creatures, real and mythical.

Romulus had been especially thrilled to see the outside of the Sema, the huge walled enclosure that contained the tombs of all the Ptolemy kings, as well as that of Alexander the Great. According to Tarquinius, his body was still on view inside, encased in an alabaster sarcophagus. He would have dearly loved to pay his respects to the greatest general who had ever lived, in whose footsteps he and Tarquinius had marched with the Forgotten Legion. But Romulus had to content himself with just seeing the site of Alexander’s final resting place. It helped him to feel that, in some way, his life had come full circle. Italy was not far away. What a pity Brennus was not with them too, Romulus thought sadly. But that had not been his fate.

Like all the other public buildings though, the Sema was shut, its tall wooden doors barred. As the sun set, its dying light turned the structure’s white marble an ominous blood-red colour.

At the same time, a bright yellow glow lit up the sky to the north.

Romulus stared in shock.

‘The lighthouse,’ said Tarquinius. ‘It can be seen thirty miles out to sea.’

There was nothing like that in the whole Republic, thought Romulus in amazement. The Egyptians were obviously a people of great ability. Everything he had seen here today proved that. And now, as it had done with so many other civilisations, Rome had come to conquer. Except, as Romulus was shortly to discover, things were not going to plan.

‘How far is the harbour?’

‘A few blocks.’ Tarquinius grinned boyishly. ‘The library is near too. Tens of thousands of books all in one place. I have to see it!’

Romulus was momentarily infected by his friend’s enthusiasm. But his fear soon returned as shouts and the clash of arms reached their ears. The noise was not far away, and it was coming from the direction that they were heading in. ‘Let’s go back,’ he urged. ‘We’ve seen enough.’

Unslinging his battleaxe, the haruspex kept walking.

‘Tarquinius! It’s too dangerous.’

There was no response.

Romulus cursed and ran after him. His friend had been right so many times before. What could he do but follow?

Each man’s destiny was his own.

It did not take long to reach the western edge of the main harbour, which was still peaceful. Here it was separated from a smaller one by a raised, man-made causeway running out to Pharos Island. At each end was a bridge which allowed ships to pass on one side of the port to the other.

‘The Heptastadion,’ revealed Tarquinius. ‘It’s almost a mile long.’

Romulus could not take his eyes off the lighthouse, which was taller and more magnificent than anything he had ever seen. ‘That’s a marvel,’ he muttered.

The haruspex watched him indulgently for a moment, but then his face grew serious. ‘Look,’ he said.

In the small anchorage to the left of the Heptastadion were nearly two score triremes. A cohort of soldiers was on guard nearby, protection for the vulnerable docked vessels.

Romulus gasped as the familiar sound of Latin carried through the cool air. There was no mistaking the troops’ identity. They were Roman.

‘Caesar’s men.’

‘Are you sure?’ Romulus asked, excitement running through him.

Tarquinius nodded, sensing that something important was about to happen. Precisely what, he could not tell.

Not that it mattered whom the legionaries served, thought Romulus. It made little difference to them which Roman general had a presence in Alexandria.

Renewed sounds of combat came from their right and they turned their heads. A few hundred paces away, past some warehouses, stood a large group of Egyptian soldiers. There were archers, slingers and light infantry to the rear, with legionaries at the front. All of them were facing away from the two friends. As they watched, a volley of stones and javelins shot up into the air, disappearing beyond the front ranks. Loud screams erupted as they landed.

‘They’ve ambushed our lot,’ cried Romulus. His mind was telling him that they should escape, but his heart wanted to fight with his countrymen. What’s the point? he thought. This is not my war.

‘You will have a choice very soon,’ said Tarquinius.

Startled, the young soldier looked around.

‘I sense a link between you and Caesar. Will you embrace or reject it?’

Before he could respond, Romulus heard the words ‘Ready above the din. His eyes were drawn back to the fighting.pila!’

Roman javelins thrown in response to the Egyptian volley came showering down on the unprotected slingers and skirmishers. There was a moment’s confusion and then they heard the legionaries charge. At the same time, burning torches were tossed out into the harbour on to the ships tethered below. Within the space of thirty heartbeats, plenty of sails were aflame.