As evening approached the Horus steered parallel to the coast, passing one of the bays that the captain had be come familiar with in the long years that he served aboard merchant vessels sailing the length and breadth of the Mediterranean. While the sun slipped below the horizon, brilliantly gilding the edges of the island's mountains and hills, those on deck stared towards the shore. A large agricultural estate lay close to the sea, and in the gathering dusk, long lines of slaves returned from their labours in the fields, groves and vineyards. Shuffling wearily, they were herded back into their compound by overseers with whips and clubs.

Cato felt Julia tremble at his side and turned to her.' Cold?'

'No. It's just that.' She indicated the last of the slaves entering the compound, and then the gates were shut and barred. 'A terrible existence for any man or woman.'

'But you have slaves at home.'

'Of course, but they are well cared for and have a degree of liberty in Rome. Not like those poor souls. Worked hard from first light to last. Treated no better than farm animals.'

Cato thought a moment before responding. 'That is the common lot of slaves. Whether they work on estates like that one, or in mines, or construction sites. It is only a small portion of them that are lucky enough to live in households like yours, or even to have the chance to train in the gladiator camps.'

'Gladiators?' Julia look ed at him with raised eyebrows.

'Lucky? How could you consider anyone lucky who suffered such a fate?'

Cato shrugged.' The training is hard, but once that's done they don't have it so bad. Their owners take good care of them and the best fighters make small fortunes and enjoy the high life.'

'As long as they survive in the arena.'

'True, but they risk no more than any man in the legions, and have a far more comfortable life than most. If they live long enough, gladiators can win their freedom and retire wealthy men. Only a handful of soldiers ever achieve that.'

'Too bloody true,' Macro grumbled. 'I wonder if it's too late to retrain as a gladiator.'

Julia stared at him. 'I am sure you don't mean that.'

'Why not? If I am going to kill people then I might as well be nicely paid for it.'

Senator Sempronius chuckled at the disgusted expression on his daughter's face. 'Ignore him, my child. Centurion Macro is joking.

He fights for the glory of Rome, not a slave's purse, no matter how loaded with gold.'

Macro cocked an eyebrow.' Now who's joking?'

Cato smiled and then looked back towards the shore. The slave compound was an ugly blot on the side of the hill overlooking the bay. All was still, save for a single flickering torch above the gate, and the dim form of a sentry standing close by as he kept watch over the slaves inside. This was the industrial side of slavery, which was largely invisible to most Romans, especially those well born, like Senator Sempronius and his daughter. The perfumed, uniformed slaves of a rich household were a far cry from the ragged masses who laboured in work camps, always tired and hungry and carefully watched for any sign of rebellion, which would be punished with brutal swiftness and severity.

It was a harsh regime, but the empire, and indeed every civilised nation that Cato knew of, depended on slavery to create wealth and feed its urban multitudes. For Cato it was a harsh reminder of the terrible differences in destiny that fate dealt out to people. The worst excesses of slavery were a blight on the world, he reflected, even if the institution was, for the present, a necessity.

He suddenly felt a faint tremor in the deck beneath his boots and glanced down.

'What the fuck?' Macro growled.' Do you feel that?'

Julia grabbed Cato's arm. 'What is it? What's happening?'

There were cries of surprise and alarm across the deck as the crew and other passengers of the Horus glanced down at the deck.

'We've run aground,' said Sempronius, as he gripped the side rail.

The captain shook his head. 'Impossible! We're too far off the shore. I know these waters. There's no shallows for fifty miles. I swear it. In any case... Look there! At the sea.'

The captain thrust out his arm and the others followed the direction and saw that the surface of the water was shimmering faintly. For a brief time that seemed far longer than it was, the dull shudder of the deck and the quivering surface of the sea continued.

Several of those on board fell to their knees and began to pray fervently to the gods. Cato held Julia in his arms and stared over her head at his friend. Macro gritted his teeth and glared back, hands clenched into fists at his sides. For the first time, Cato thought he saw a glimmer of fear in the other man's eyes, even as he wondered what was happening.

'A sea monster,' Macro said quietly.

'Sea monster?'

'Has to be. Oh, shit, why the hell did I agree to travel by sea?'

Then, as suddenly as it had begun, the faint shuddering stopped, and a moment later the surface of the sea returned to its steady chop as the Horus gently rose and dipped on the easy swell. For a moment no one on the ship moved or spoke, as if they were waiting for the strange phenomenon to begin again. Julia cleared her throat.' Do you think it's over, whatever it was?'

'No idea,' Cato replied softly.

The brief exchange had broken the spell. Macro puffed his cheeks as he let out a deep breath and the ship's captain turned away from his passengers and scowled at the steersman. The latter had released his grip on the tiller of the great paddle at the stern of the Horus and was cowering beneath the fantail decoration overhanging the stern post. Already the ship was slowly swinging round into the wind.

'What in Hades do you think you're doing?' the captain blazed at the steersman.' Return to your bloody post and get us back on course.'

As the steersman hurriedly took up the tiller, the captain turned round to glare at the other sailors. 'Back to work! Move yourselves.'

His men reluctantly returned to their duties as they adjusted the sail that had begun to flutter at the edges as the Horus luffed up for a moment, before the steersman leaned into the tiller and the ship settled back on to her original course.

Macro licked his lips nervously. 'Is it really over?'

Cato sensed the deck under his feet, and glanced at the sea, which looked just as it had before the tremor had begun. 'Seems to be.'

'Thank the gods.'

Julia nodded, then her eyes widened as she recalled her maid, who had been resting on her mat in the small cabin she shared with her mistress and the senator. 'I'd better check on Jesmiah. Poor girl will be terrified.'

Cato released her from his arms and Julia hurried across the deck towards the narrow gangway leading down to the passengers'

quarters, where those who could afford it had paid for a cabin. The rest of the passengers simply lived and slept on the deck of the Horus.

As Julia disappeared from sight, a faint cry reached them from the shore and Cato, Macro and Sempronius turned towards the land.

Though the light was dim, they could clearly see figures stumbling away from the estate's slave compound. Or what was left of it. The walls had been flattened, exposing the barrack blocks inside. Only two were still standing; the rest were in ruins.

'Bloody hell.' Macro stared at the ruins. 'What could have done that?'

'An earthquake,' said Sempronius. 'Has to be. I've experienced something like it before while I was serving as a tribune in Bythinia.

The earth shook, and there was a dull roar. It went on for some moments, and shook some buildings to pieces. Those inside were crushed and buried under the rubble.' He shuddered at the memory.

'Hundreds died...'