‘Where did you take him?’

I spun around to see Sigurd emerging from the stair behind me. He was breathing heavily, though still could hold his axe with a single hand.

‘To a monastery.’ I hesitated, suddenly thinking what he might do to the boy who had tried to kill the Emperor. Of course a murderer deserved death – but I had saved his life, and I had not shaken the soldier’s superstition that you buy a man’s life only with a small piece of your own.

‘Which monastery?’ Sigurd demanded. ‘Christ! The boy might already be gone. There’s no time.’

‘The monastery of Saint Andrew. In the Sigma district.’

‘Follow me.’

His armour jangling like shackles, he led me at a run through the corridors of the palace. The scribes and noblemen we passed stared but said nothing; no guards challenged us. Doors opened before us as if by some unseen hand, and sometimes it seemed that a room which I had seen cast in darkness as we approached was bathed in light when we arrived. Then the lamps became scarcer, the stairs steeper. There was little life in this part of the palace, and that, mostly furtive-faced slaves scurrying past with their eyes cast down. I hastened to keep close to Sigurd.

At length the columns and marble floors gave out and we came into a low tunnel. Sigurd nodded to the brick vaults above our heads.

‘The hippodrome.’

We passed under it in silence, our footsteps mute on the sandy floor. There was a gate at the end and Sigurd had the key: beyond it I could hear sounds of life, of laughter and labour, and smell the warm odour of horses.

‘Hipparch!’ bellowed Sigurd. ‘Hipparch! We need two horses, saddled and bridled.’

‘Late for your mistress again?’ A tall man, elegantly dressed, stepped into the square of the stable yard.

‘At least I have a woman, you horse-fucker.’ Sigurd clapped him on the shoulder. ‘But she will have to wait.’

The hipparch raised his eyebrows. ‘So urgent? I have two mounts awaiting the logothete’s dispatches.’

‘Then the dispatches can wait too. Send a boy to the chamberlain and tell him we’ve gone to the monastery of Saint Andrew, in Sigma.’ A thought struck him. ‘You can ride, can you, Demetrios?’

I could, although galloping a horse bred for the imperial post through the darkening streets of the megapolis was not something I was practised in. It taxed all my luck and concentration merely staying upright on the beast, and it was a mercy that with the day ending the crowds were gone, and that the emerging watchmen had the wit to retreat into the arcades as Sigurd and I thundered past.

We arrived at the monastery, Sigurd sliding off his horse and crossing swiftly to the gates. They were locked, but the butt of his axe-shaft was soon pounding out notice of our arrival loud enough to reach the ears of the dead in the distant necropolis.

A small door set within the gate cracked open a finger’s breadth.

‘Who’s there?’ Suspicion and fear had driven all trace of sleep from the speaker’s mouth.

‘Sigurd, captain of Varangians and guardian of Emperors. You keep a boy with you who I need to see.’ Sigurd shouted the words like a challenge in the arena.

The monk, to my surprise, found sufficient moral indignation to resist.

‘The monastery is closed for contemplation and prayer. You may return in the morning. No-one passes the gate during the hours of darkness.’

‘I have almost lamed two of the logothete’s finest horses to come here.’ Sigurd was working himself into a powerful frenzy. ‘I will not now sit on your doorstep.’ Without warning, he lifted his boot and slammed it into the wooden door; there was a yelp of pain as it swung inwards.

We stepped through, Sigurd scraping his shoulders on the frame. Inside a monk was rubbing a bruised shoulder, and cursing us with words that no man of God should know, but we ignored him as I led the way across the courtyard to the arched doorway where I had left the boy. Forestalling Sigurd’s axe, I knocked.

‘One day your patience will betray you,’ Sigurd fretted as we waited in the cold darkness. ‘If this doctor’s in there, let me call him out.’

‘One day you’ll knock down the wrong door,’ I told him, ‘and find so many enemies your axe will be blunted before you can kill all of them.’

Sigurd shrugged. ‘Then I’ll beat their heads in with the haft.’

‘And leave another to clean their wounds.’

We both looked to the door, which had silently opened to reveal the woman doctor to whom I’d entrusted the boy. She held a candle, and wore only a long woollen shift which left her arms and feet entirely bare. There were rises in the fabric where her nipples pressed against it: the sight of them stirred something within me, but the look on her face was of pure anger.

‘What do you mean by hammering down the monastery gates at this hour, and then calling me from my work? If you must profane the laws of God, you might at the least respect the business of healing.’

‘We seek the boy who was brought here this morning,’ said Sigurd, before I could offer an apology. ‘Is he here?’

She gazed at him contemptuously, while my heart raced to hear the answer. Had we come so close, only to be denied our prize by my compassion?

She tossed her head. ‘He’s here. He could hardly have left. He cannot stand, let alone walk. At the moment he sleeps.’

‘We must see him. Immediately.’ Sigurd’s voice was heavy with menace. ‘We come on palace business.’

Two flames were reflected back in the doctor’s dark eyes. ‘The Emperor himself cannot raise a sick boy to health simply by his command. The boy is feverish and delirious. At the moment he is sleeping, and that is probably the most wholesome thing he has done in a month. Unless you are the man who sliced so deeply into his leg, you would tremble to wake him.’

‘Lady, I am the man who stopped the Bulgar from killing him.’ Sigurd’s voice was loud now, and he stepped forward so that he almost touched her. She was minute before him, like Andromeda beneath the Kraken, but she did not waver.

‘No,’ she said. ‘While the boy sleeps, you wait.’

‘What if he escapes by the back door?’ Sigurd was in retreat, now, but he would not surrender until he was satisfied.

‘There is no back door, Captain – only two high windows through which you would struggle to fit your forearm. Good night.’ And blowing out the candle, she left us in darkness. On the far side of the door I heard a bolt shoot home.

Sigurd stood very still, staring at his axe where it caught the moonlight.

‘You can’t chop your way in,’ I warned wearily. I sat down on the step and leaned my back against the base of a column. ‘And the boy won’t move. What can we do but wait?’

Sigurd clearly had many ideas, but with a reluctant growl he at last laid his weapon on the stone floor and made a seat beside it.

‘We don’t move,’ he warned me. ‘And we don’t sleep. Anyone who comes out of that door before dawn will find my axe through their throat.’

I did not ask what would happen to me if I failed to stay awake.

‘Your zeal in defence of the Emperor is like something out of legend,’ I said quietly, thinking he could ignore me if he chose. ‘No wonder he prizes his Varangians so highly.’

‘Only the English.’ Sigurd stared moodily at his fist. ‘There were others in the guard, Rus and Danes and their sort, but he expelled them because he could not trust them.’

‘Why the English?’ I was genuinely curious: to me one fair-headed barbarian giant seemed much like another.

Sigurd grunted. ‘Because the English are the only men who will hate the Emperor’s enemies as if they were his own. I will tell you. Fifteen years ago, at a battle near Dyrrachium, the Normans trapped a company of Varangians in a church. At first they offered gold, and riches, if the English would desert the Emperor and join them in battle, for they knew of our fame in war, but the Varangians refused. Then they grew angry, and threatened to slaughter them to the last man if they did not surrender, but still the English defied them. So at last they set fire to the holy sanctuary where they had sought refuge, and razed it to the ground. Not one man escaped. We would rather the Normans burn us alive than surrender to them. That is how deep the hatred goes.’

‘But why? Why leave wives as widows, when they could have been safely ransomed after the battle?’

Sigurd leaned forward. ‘Because the Normans killed our king and stole our country. Their bastard duke tricked and lied his way onto our throne, then laid the land waste.’

‘When was this?’ He spoke with such a savagery that it could have been yesterday.

‘Thirty years ago. But we do not forget.’

‘You would have been a child thirty years ago, no more than five or six years old. The same as me.’

A sound from the door behind us broke off our conversation. Before I could even turn my head Sigurd was on his feet and lifting his axe, poised to strike. I had a flash of panic that he would behead some innocent monk attending a call of nature, but it was not a monk, nor yet the boy escaping: it was the doctor. She had wrapped a stola around her shoulders, covering the indecency of her shift, and held two steaming clay bowls in her hands. Had it been me, I thought, I would probably have dropped them in the face of a lowering Varangian, but she simply set them down on the floor before us.

‘Soup,’ she said. ‘I thought you might be cold. I did not want to find a pair of obstinate men with frostbite in the morning.’

Sigurd resumed his seat, and we tipped the hot food eagerly down our throats. The lady stood over us, watching, until we had wiped the bowls clean with the bread she gave us. To my surprise, she did not then retreat inside with them; instead she smoothed her skirts under her legs and seated herself on the steps between us.

‘It’s cold out here,’ I warned, my clouded breath illustrating my words.

‘Indeed,’ she agreed. ‘Too cold for two men to sit here all night keeping an unconscious cripple from wandering out of his bed.’

‘We do not merely guard against his escape. There are men out there who would ensure he never left his bed again, if they could reach him.’

‘And what do you want with him then?’ she pressed. ‘To offer him prayers to speed his recovery?’

‘Justice,’ said Sigurd harshly.

‘Tell me, how did you come to be a doctor?’ I interrupted, hurriedly pushing the conversation into less contentious grounds. ‘And in a community of monks at that? I am Demetrios,’ I added, aware that none of our unruly meetings had yet yielded an introduction. ‘This is Sigurd.’

‘I am Anna. And I am a doctor care of a wise father and a crass lover. My father taught me to read and learn the knowledge of the ancients – the texts of Galen and Aristotle. My lover, to whom I was betrothed, chose to abandon the marriage at the last minute. After that humiliation, none would marry me, so after the tears I chose this profession. I had friends who had suffered at the hands of incompetent surgeons, men who knew no more of a woman’s body than of a camel’s. I thought I could do better.’

She pressed her palms together, and in the moonlight I saw that despite her cloak she was shivering.

‘Do you think me shameless?’ she asked. ‘Telling near strangers my intimate history?’ She leaned forward. ‘I see a dozen patients a day, and every one of them asks me my story. You grow used to it.’

‘You could tell them you were inspired by the example of Saint Lucilla,’ suggested Sigurd gruffly.

Anna laughed. ‘Perhaps that would have been easier. As for the monks, their typikon commands them to provide a hospice with doctors who can minister to all the sexes. Usually there are two of us, but my colleague died last spring and they have not replaced him. So I do the work of two.’

I nodded. ‘And is that better than marriage?’

Again she laughed. ‘Mostly. Sometimes men propose it, but it is hard to be stirred by a man when you have searched the contents of his bowels for evil humours. The monks, of course, fear that I will pollute their thoughts, and keep their distance as much as they can.’

Probably they thought her a perfect succubus, hovering in their tormented dreams, but I did not say so.

‘And what of you?’ she asked. ‘The strange man who brings me dying youths in the morning, and demands them back in the evening. Do you work for the Emperor, like your companion?’

‘I work for myself,’ I said stoutly.

‘No man works for himself.’ I was surprised by the force of her statement. ‘Men work for greed, or for love, or for vengeance or for shame.’

‘Then I must work for greed, I suppose. And for other men’s revenge.’ I thought on this. ‘In this case, the Emperor’s.’

‘And how, Demetrios, did you become the angel of the Emperor’s vengeance?’

I gestured to the monastic walls around us. ‘I started in a place much like this, a monastery in Isauria. My parents sent me.’

‘Did the life of a novice agree with you?’

‘The food was plentiful, and regular. I had a taste for butter, which my parents could not provide, so I stayed.’

‘But not forever?’

I shook my head. ‘When I was fifteen I ran away to join the army. I wanted to kill Turks and Ishmaelites.’

‘And did you?’

‘No. The generals were too busy using their armies against each other, trying to put themselves on the imperial throne. The only chance I had to kill Turks was when we fought a lord who had hired them as mercenaries. I did not want to die with an arrow in my throat because our noble families had carried their feuds across the empire, so I went to work for myself. At least I could choose my causes. A merchant hired me to guard him and I failed, so to save my reputation I found his killers and killed them myself. Then I discovered others needed similar services.’

‘So you were a bounty hunter?’

‘Yes,’ I admitted. ‘Not a proud occupation, but a lucrative one. And as my name spread and my clients grew more illustrious, the burden of the work moved from exacting revenge to revealing the guilty. Clerks who stole from their masters, uncles who abducted their nieces and held them hostage, sons who killed their fathers for the inheritance.’

‘And how did your wife view your profession?’

I looked up sharply. ‘What of my wife?’

‘What of the ring on your finger?’

She pointed to my right hand, where I still wore the thin lover’s band I had first put on sixteen years ago. I had been nineteen, flushed with love and excitement and the weight of my first-earned coins in my pocket: I had insisted we go to the grandest goldsmith on the Mesi, though all my new riches afforded only the least of his jewellery. Later I found that he had swindled me even of that, that it was merely a cheap alloy coated with gold, but by then it was on my finger and I was too proud to take it off. Even now.

‘My wife is dead. She died seven years ago, haemorrhaging from her womb.’

Unexpectedly, Anna reached over and took my hand in hers, stroking it softly. ‘I’m sorry. I should not pry.’

‘You wouldn’t know where not to pry if you didn’t ask,’ I said struggling with the calm and discomfort I felt in her touch. There was a stab of disappointment when she let go.

‘Besides,’ I said. ‘I’m speaking too much.’ That was a rare complaint, but – like the touch of her hands – I was finding it at once unnatural and relieving. There was something about this woman’s confidence that invited confession. ‘Sigurd must be bored hearing me prattle about my past.’

We both looked over to him, and Anna stifled a giggle. It seemed I had indeed bored the Varangian, so much so that he lay with his head against the column, fast asleep.

I thought Anna would be cold, or tired, but she made no move to leave; we talked on through the night in hushed voices, until at length even my eyes began to drift closed. The pauses between my sentences lengthened, and once it was only a playful slap on my knee that kept me from joining Sigurd in the world of dreams. Anna stood, stretching her arms above her so that her body pressed tight against her cloak.

‘I should sleep,’ she said. ‘There will be other patients to see tomorrow, as well as the boy. There is a spare bed in the infirmary if you want to come in out of the cold, Demetrios.’

Though there was not the least implication of lewdness in her plain words, I still blushed.

‘What about Sigurd?’ I asked.

Anna leaned over and put the back of her hand against his cheek. ‘He’s warm enough.’

‘He comes from a frozen island at the edge of the world.’ I wondered why I stiffened when I saw her touch his face. ‘He probably grew up in castles built of ice.’

‘I’ll lay a few more blankets over him. He’ll come inside if he wakes up cold.’

Anna left me in the infirmary, having assured me that there were no lepers or plague-ridden unfortunates beside me. Huddling under the covers I was soon lost in dreams, until the cock crowed and the monks filed into their chapel, and Sigurd came thundering through the door swearing he would be delayed no more.