'But if it's an earthquake, then why were we affected, out here at sea?'

'I don't know, Macro. The work of the gods is beyond the understanding of men.'

'Perhaps,' Cato remarked. 'But surely, if the tremor on land is severe enough, it would communicate itself through the water to us?'

'That may be so,' Sempronius admitted. 'In any case, we're the lucky ones. It is those on land who will have felt the full power of the gods' wrath.'

For a moment the three men stared towards the ruined slave compound, slowly slipping into the distance as the Horus sailed steadily away from the coast. A fire had broken out in the ruins, most likely from the kitchens preparing the evening meal, Cato decided.

Flames licked up into the dusk, illuminating the shocked figures of the survivors. A handful were desperately picking away at the rubble to free those trapped beneath. Cato shook his head in pity.

'Be thankful we are at sea. I would not want to be ashore now. You should be grateful for that at least, Macro.'

'Really?' Macro replied quietly. 'What makes you think the gods have finished with us yet?'

'Deck there!' a voice suddenly cried from aloft. 'Captain, look!'

The sailor sitting astride the spar close to the top of the mast had thrust his spare arm out, along the coast to the west.

'Make your report properly!' the captain bellowed up to him.

What do you see?'

There was a pause before the sailor replied anxiously. 'I don't know, sir. Never seen its like. A line, like a wall, right across the sea.'

'Nonsense, man! That's impossible.'

'Sir, I swear, that's what it looks like.'

'Fool!' The captain crossed to the side of the ship, swung himself up on to the ratlines and began to clamber aloft to join the lookout.

'Now then, you bloody fool, where is this wall of yours?'

The lookout thrust his hand towards the horizon, into the fading light of the setting sun. At first the captain could see little as he squinted. Then, as his eyes adjusted to the distant gleam, he saw it. A faint glitter of reflected light rippling along the horizon, above a dark band that stretched from out to sea right up to the coast of Crete.

Where it touched the land there was a churning foam of water.

'Mother of Zeus,' the captain muttered as his guts instantly turned to ice. The lookout was right. There was a wall ahead of the Horus, a wall of water. A vast tidal wave was sweeping along the coast directly towards the ship, no more than two or three miles away and racing towards them faster than the swiftest of horses.

CHAPTER TWO

Atidal wave?' Cato's eyes widened. 'How big?'

'Big as a bloody cliff,' the captain replied. 'And heading this way, straight along the coast.'

'Then we must alter course,' said Sempronius. 'Get out of its way'

'There's no time for that. In any case, the wave stretched as far as I could see. We can't avoid it.'

The senator and the two centurions stared at the captain for a moment before Sempronius spoke again. 'So, what now?'

'Now?' The captain gave a brittle laugh. 'We say our prayers and make our final farewells and wait until the wave hits us.'

Cato shook his head.' No. There has to be something you can do to save the ship.'

'There's nothing, I'm telling you,' the captain said bleakly.

'You haven't seen the size of that thing yet. But you will, any moment.'

All eyes turned towards the horizon, and then Cato noticed what looked like a dark shadow on the rim of the world, at the moment only a fine line and one that looked wholly unthreatening as yet. He stared at it briefly before turning back towards the captain. 'You've been in storms before, haven't you?'

'Oh, yes. Storms are one thing. A tidal wave is something else.

There's no hope for us.'

'Bollocks!' Macro growled, and then grabbed the captain's tunic in both hands and drew the Greek close to his face. 'There's always hope. I haven't survived fuck knows how many fights and injuries just to die on this tub. Now then, I ain't a sailor. That's your job.

You've got a dangerous situation on your hands. So you deal with it.

Do what you can to give us the best chance to live through this. You understand me?' He gave the captain a shake. 'Well?'

The Greek wilted before the intense gaze of the centurion and nodded. 'I'll do what I can.'

'That's better.' Macro smiled and released his grip.' Now then, is there anything we can do to help?'

The captain swallowed nervously. 'If you don't mind, it would be best if you stayed out of the way'

Macro's eyes narrowed. 'Is that all?'

'You could tie yourself to the mast, or one of the cleats, to save yourselves from being swept over the side when the wave hits us.'

'All right then.'

The captain turned away to shout orders to his crew and the sailors hurried aloft to shake out the reefs in the huge mainsail. At the stern, the steersman strained at the tiller, turning the Horus towards the sunset.

'What is he doing?' asked Sempronius.' The fool is heading straight for the wave.'

Cato nodded. 'Makes sense. The bows are the strongest part of the ship. If we meet the wave head on, we might break through it, if we can't ride over it.'

Sempronius stared at him. 'I hope you are right, young man. For your sake, my sake and all our sakes.'

As soon as the senator had spoken, Cato's mind focused at once on Julia and he called to Macro as he hurried towards the gangway leading to the cabins.' Get yourself tied to the mast, and take the senator with you.'

'Where are you going?'

'To get Julia and Jesmiah. They'll be safer on deck.'

Macro nodded, then glanced towards the horizon, and now he could see the wave more clearly, rising up in a great bar that extended far out to sea, while the other end foamed and crashed along the coast. 'Be quick, Cato!'

Cato ran across the deck and jumped down the short flight of steps into the passengers' quarters, where thin stalls accommodated those who had paid the most for their passage to Rome. Thrusting aside the canvas curtain that formed the makeshift entrance to Julia's quarters, he ducked his head inside. Julia sat on the deck, cradling Jesmiah in her arms.

'Cato! What's the matter?'

'No time to explain.' He stepped towards her, stooped and drew her up on to her feet. Jesmiah scrambled up at her side, wide-eyed with terror.

'Master Cato,' her lips trembled, 'I heard some one say there's a monster.'

'There's no monster,' he snapped, thrusting them both out of the stall and up towards the gangway. 'We have to get on deck, as quick as possible.'

Julia stumbled up the steps towards the deck. 'Why? What's happening?'

With a quick glance at Jesmiah Cato replied, 'Trust me and do as I say'

They emerged on to the deck in a scene of terror and chaos.

Macro had tied the senator to the foot of the mast and was hurriedly doing the same for himself. All around the other passengers and crew were doing the best they could to secure themselves to the vessel. The captain had joined the steersman on the small steering deck and both men braced their arms on the tiller and stared grimly ahead.

Jesmiah stared round in horror and drew up.

Cato grabbed her arm and dragged her roughly towards the mast.

'Come on, girl! There's not much time.'

As soon as they reached Macro and Sempronius, Cato thrust Julia and her maid down on to the deck and took up the tail end of the rope Macro had used to secure himself to the mast. Glancing up, he saw that the wave was much closer now, travelling at an extraordinary speed as it swept along the coast. He snapped round to the two women.

'Raise your arms!'

Running the rope round their stomachs, Cato circled the mast and tied the end into the loop round Macro's waist.