The haruspex grinned. ‘It’s made by grinding up a particular type of blue-green fungus.’

Brennus was incredulous. ‘Like the stuff that grows on bread?’

‘Perhaps. Or on some varieties of over-ripe fruit. I have never been able to tell,’ sighed Tarquinius. ‘Many moulds are poisonous, so it’s difficult to experiment with them.’

Romulus was intrigued by the incredible concept that something growing on rotting matter might prevent the inevitable, fatal illness that followed belly wounds or animal bites.

Resentment bubbled up in Brennus. ‘It’d be better saved for our comrades.’

‘Indeed.’ Tarquinius’ dark eyes regarded him steadily. ‘However our lives depend on Pacorus recovering.’

The Gaul sighed. He was not worried about himself, but Romulus’ survival was vital to him. And Tarquinius held the key to that, he was sure of it. Which meant that Pacorus had to pull through as well.

During the whole experience, the Parthian had not even opened his eyes. Only his faint breathing showed that he was still alive.

Sitting back, Tarquinius considered his handiwork. He went very quiet.

Romulus looked at him questioningly. It was the same way the haruspex behaved when he was studying the winds or cloud formations in the sky.

‘He has a small chance,’ pronounced Tarquinius at length. ‘His aura has strengthened a little.’ Thank you, great Mithras.

Romulus breathed a small sigh of relief. They might survive yet.

‘Sit him up so I can place the bandages.’

As the servants obeyed, the Etruscan ripped several sheets into suitable sizes. He was about to begin wrapping Pacorus’ midriff when the door suddenly slammed open. As the sentry snapped to attention, eight brown-skinned men barged into the room, their dark eyes angry and concerned. Dressed in fine cloth tunics and richly embroidered tightly fitting trousers, they wore sheathed swords and daggers on belts inlaid with gold wire. Most had neatly trimmed short beards and black, coiffed hair. ‘What’s going on?’ shouted one.

Everyone except Tarquinius tensed. Romulus, Brennus and Felix jerked upright, staring straight ahead as if on parade. These were some of the Parthian senior centurions, the highest-ranking officers in the Forgotten Legion. Men who would be responsible for the legion if Pacorus died.

Still held in a sitting position by the servants, Pacorus’ head lolled forward on to his chest.

The newcomers gasped.

‘Sir?’ asked another, bending down and trying to attract Pacorus’ attention.

There was no response.

Rage filled the man’s features. ‘Is he dead?’

Romulus’ pulse quickened and his eyes darted to Pacorus. He was immensely relieved to see that the Parthian was still breathing.

‘No,’ said Tarquinius. ‘But he is near death.’

‘What have you done?’ barked Vahram, the primus pilus, or senior centurion, of the First Cohort. He was their own direct superior. A barrel-chested, powerful man in early middle age, he was also the legion’s second-in-command. ‘Explain yourself!’

Struggling not to panic, Romulus prepared to draw his gladius. Brennus and Felix did likewise. It was impossible to miss the threat in Vahram’s words. These were no mere guards to intimidate and, like Pacorus, the senior centurions held the power of life and death over them all.

His nostrils flaring, Vahram gripped his weapon.

Tarquinius lifted his hands calmly, palms facing Vahram. ‘I can clarify everything,’ he said.

‘Do so,’ replied the primus pilus. ‘Quickly.’

Romulus’ fingers slowly released his gladius hilt. He stepped back, as did Brennus and Felix. It felt as if they were all teetering on the edge of a deep chasm.

In stony silence, the Parthians convened around the bed. Vahram scanned the others’ faces suspiciously as he listened to the haruspex’ account of what had happened. Of course no mention was made of returning to Rome.

When Tarquinius finished, no one spoke for some moments. It was hard to tell if the Parthians believed his story. Romulus felt very uneasy. But the die had been cast. All they could do was wait. And pray.

‘Very well,’ said Vahram at last. ‘Things could have happened as you say.’

A slow breath escaped Romulus’ lips.

‘Just one more thing, haruspex.’ Vahram’s hand fell lightly to his sword. ‘Did you know this would happen?’

The world stopped and Romulus’ heart lurched in his chest.

Again everyone’s eyes were fixed on Tarquinius.

Vahram waited.

Incredibly, the haruspex laughed. ‘I cannot see everything,’ he said.

‘Answer the damn question,’ growled Vahram.

‘There was great danger, yes.’ Tarquinius shrugged. ‘There always is in Margiana.’

The tough primus pilus was not satisfied. ‘Speak clearly, you son of a whore!’ he shouted, drawing his sword.

‘I thought that something might happen,’ admitted the haruspex. ‘But I had no idea what.’

Romulus remembered the watching jackal and how he and Brennus had stayed away from the fire to study it. A decision which had saved their lives. Was that not proof of a god’s favour? He looked at Mithras crouching over the bull and trembled with awe.

‘That’s all?’ demanded Vahram.

‘Yes, sir.’

Romulus watched the primus pilus’ face carefully. Like that of Tarquinius, it was hard to judge. He did not know why, but suspicion filled him.

‘Very well.’ Vahram relaxed, letting his blade drop to his side. ‘How long will it be before Pacorus recovers?’

‘He may never do so,’ replied the haruspex levelly. ‘Scythicon is the most powerful poison known to man.’

The senior centurions looked anxious and a vein pulsed in Vahram’s neck.

Pacorus moaned, breaking the silence.

‘Examine him again!’ barked one of the younger officers.

Tarquinius bent over the bed, checking Pacorus’ pulse and the colour of his gums. ‘If he lives, it will take months,’ he pronounced at last.

‘How many?’ asked Ishkan, a middle-aged man with jet-black hair.

‘Two, maybe three.’

‘You will not leave this building until he is well,’ the primus pilus ordered. ‘For any reason.’

There was a growl of agreement from the others.

‘My century, sir?’ Tarquinius enquired.

‘Fuck them!’ screamed Ishkan.

‘Your optio can take charge,’ the primus pilus said curtly.

Tarquinius bowed his head in acknowledgement.

Brennus and Felix relaxed. A reprieve had been granted, but Romulus was not happy. Later he would realise, bitterly, that the feeling had been intuition.

‘We’ll leave you to it.’ Vahram turned to go, and then swiftly spun on his heel. Snarling silently, he rushed at Felix with his sword raised. The little Gaul had no time to reach for his own weapon. Nor did his friends.

Vahram ran his blade deep into Felix’ chest. The lethally sharp iron slipped between the little Gaul’s ribs to pierce muscle, lungs and heart, emerging red-tipped from his back.

Felix’ eyes widened with horror and his mouth opened. No sound came out.

The senior centurions’ faces were the picture of shock.

Tarquinius also looked stunned. He had forgotten the heavy price that gods often required. They gave nothing away free. Normally, he would have sacrificed an animal when seeking important information. Tonight, Mithras had revealed much without any obvious payment. Anguish filled the haruspex. How could he have been so stupid? Elated at seeing a vision, and at the mere possibility of returning to Rome, he had failed to consider what might follow. Was Felix’ life worth that much?

And then Tarquinius’ vision filled with the image of Romulus, standing on the deck of a ship, sailing into Ostia, Rome’s port. After the drought of the previous few months, it felt like a rainstorm. Felix had not died in vain, he thought.

But Romulus knew none of this. Grief flooded through him. Felix was completely innocent; he had not even been at the Mithraeum. In reflex, Romulus drew his weapon and took a step towards the primus pilus. Brennus was right behind, his face fixed in a rictus of rage. They were two against eight, but at that exact moment, neither cared.