Sigurd frowned at Anna, who stood at the boy’s feet and showed no intention of leaving.

‘We won’t torture him,’ he said. ‘Just talk.’ He rubbed the back of his neck; I guessed it was stiff from a cold night on a stone pillow. ‘But there are things to say which you should not hear.’

To my relief, in all our talk the night before Anna had never pressed me for what we wanted with the boy. Now, though, she folded her arms across her chest and met Sigurd’s ill-temper square on.

‘You cannot talk to him,’ she told him. ‘Not without me.’

‘I will talk to him, lady, whether you want it or no.’ Fatigue and frustration did not sit well with Sigurd. ‘And if I say that you will not be part of it, then either you will go outside until I call for you, or I will have my men drag you down to the imperial dungeon to learn obedience.’ A dozen Varangians had come to the monastery at dawn, taking up stations at the doors and gates to the obvious alarm of the monks.

Anna hardened her grip on the bedstead. ‘And which of you speaks Frankish?’

Now both of us stared at her in confusion. ‘Frankish?’ I echoed. ‘Why should either of us speak Frankish?’ I could see from Sigurd’s silence that he no more knew the tongue than I.

‘Because if you don’t, you may as well talk to a fish. I spent all day with the boy yesterday, and all he spoke or understood was Frankish.’

‘And you, of course, spoke and understood it too.’ Sigurd’s face boiled with fury, but Anna simply shrugged.

‘Enough. So near to the gates I see many pilgrims in my work; many are Franks. A doctor who cannot get her patient to tell her their ailments is unlikely to work many cures.’

There was a hostile silence. Curse the monk, I thought, for employing this barbarian rabble of Bulgars and Franks. Whether he’d worked deliberately, or with the only men he could find, he had thrown every possible obstacle into our path.

‘We’ll take him to the palace,’ said Sigurd at last, his voice alive with anger. ‘One of the secretaries will speak Frankish. And we should keep the boy somewhere he can’t escape.’

‘If you move that boy, least of all into a prison, he will be dead before sunset.’ Anna was unmoved by Sigurd’s temper; indeed, she seemed to draw strength from it and breathe it straight back at him.

‘He should die anyway.’ Sigurd was now squeezing his fist around his axe-shaft, as if crushing a man’s neck; I feared that soon the violence in his words would manifest itself in his hands. ‘For his crime, death is the only justice.’

‘We do not want the boy to die.’ I spoke forcefully, glaring at Sigurd and Anna together. ‘If the doctor says we cannot move him, then we will not move him.’ I gestured around the room: its few windows were small enough that a bird could hardly have flown through them. ‘If we have a guard on the door, and another within, the boy will be safe from harm and barred from escape. Now as we have waited a long night to speak with him, and as every minute we waste gives time and aid to the Emperor’s enemies – with whom this boy is our only link – I propose we use Anna’s gifts immediately.’

Sigurd’s chest swelled so tight I thought he might burst free of his armour. He clashed the greaves on his forearms together, then slammed a fist onto the wooden table beside him.

‘I will go to the palace and find someone who speaks Frankish,’ he said, his voice brittle with bridled anger. ‘Someone trustworthy. What you choose to do before I return is your own business, Askiates, but you will answer for it alone.’

‘I will answer to the man who pays me,’ I said. I was growing bored of Sigurd’s rages, though I never imagined he did it in bluff. ‘And he does not pay me for dallying.’

With a final, derisive snort Sigurd stormed out of the room, berating his men for imagined inadequacies as he passed them in the courtyard. Then all was still: through the window I heard the low tenor of the monks’ liturgy.

I looked at Anna, shame clouding my face. ‘I apologise for his temper. He has too much faith in fists and swords, and a consuming regard for his duty.’

She gave a thin smile. ‘You’re not to blame. But if you want to make best use of your time, you had better leave too.’

‘What? Did you not hear what I told him? I need to speak with the boy immediately.’

‘You’ll learn more from the boy if you sit out there on the steps. Look at him. You and the guard have frightened him half to death – and death was already far too near for comfort.’

It was true. While we talked the boy had shrunk beneath his blanket, and now he clutched at the pillow like a mother. His eyes were clenched shut.

‘Tell me what you want to ask him,’ Anna insisted. ‘Tell me, then leave me alone with him.’

For a moment I hesitated, searching her face for signs of treachery. Could I trust her? If word escaped that a boy had come within a hand’s breadth of murdering the Emperor, and was now quartered here in the monastery, there would be uproar. None of us would be safe, myself not least. But by facing down Sigurd I had committed myself – and my trust – to Anna: she would have to know all, unless I wanted him to return triumphant. That was not something my pride would admit.

With a deep breath and a pounding heart, I told Anna everything. The assault on the Emperor; the pimp Vassos; Kaloyan the Bulgar and the strange monk who employed him; and how we had found the boy. I even told her about the tzangra, the barbarian weapon of miraculous strength, for I was particularly eager to learn what the boy knew of it. When at last I had finished I took her advice: I walked outside, staved away the suspicious glances of Sigurd’s guardsmen, and settled myself on the steps in the fresh morning air. There I waited.

‘Won’t you wait for your friend?’ Anna asked. ‘He should be back soon.’

Or not. I doubted he would have the loan of any more of the hipparch’s beasts after the use we had given them in the night.

‘I think it would be wiser to leave. There are elements of the boy’s story I must investigate.’ And it would irritate Sigurd immeasurably to find me gone. ‘I suppose Sigurd will tell you exactly what he demands, but on no account let him take the boy away from here.’

Anna bared her teeth. ‘Let him try.’

‘Good.’ The boy was too valuable to be left in the care of gaolers and torturers, and wounds like his would rot into his bones in the foetid dungeon air. Nor could I shake off the mounting sense that part of my life was now invested in his.

‘I will be back this evening, or maybe tomorrow.’

‘I shall look forward to it.’

Strangely warmed by those parting words, I left the monastery and hastened towards the city, keeping off the main road to avoid any encounter with Sigurd. I visited the docks, the workshop of Lukas the fletcher, and a man who sold me three withered gourds; then I retired to the fields near the western walls, where I passed the afternoon straining my shoulders and frightening a watching flock of crows. Finally, weary but satisfied, I made my way back to the palace.

‘It’s as well you came to my door, Demetrios. Your name has been spoken often in the palace today, and rarely with favour.’

‘Sigurd?’

‘Indeed.’ Aelric shifted the weight of his axe a little. ‘He swears you are an agent of those who would harm the Emperor. That is, when he does not curse you for a mercenary intent only on impoverishing the treasury.’

I snorted; I had heard enough gibes about money. ‘And why does Sigurd fight for the Emperor? Is he a Roman, fighting to preserve his ruler and his nation? No. He fights for the same motives as all the other Patzinaks, Turks, Venetians and Norsemen in our legions: gold, and glory. Many would say they were the only things worth fighting for.’

A dark look crossed Aelric’s lined face. ‘Do not doubt Sigurd’s devotion to Byzantium, Demetrios. He takes the gold and cherishes his glory, as every warrior should, but he loves the Emperor like a monk loves his God. If the Emperor was hemmed in by countless hosts of enemies, and all was lost, Sigurd would be the last man left standing beside him – whether there was gold to pay him or not. Of how many Turks and Patzinaks could you say that?’

I rolled my eyes. ‘A believer may be blessed, but a zealot is dangerous – and his love too easily turns against itself. Anyway, I came to speak with the chamberlain, Krysaphios, not with Sigurd.’

‘You have a gift for him, do you?’ Aelric peered at the bundle I held under my arm. It was broad and flat, and wrapped about with sackcloth; it might have been a painted icon, though it was not.

‘Something he will want to see,’ I said. ‘If I am not banned from the palace for wanting to keep valuable witnesses alive until they have told their tale.’

Aelric nodded. ‘Krysaphios will see you.’

With a last suspicious glance at my package, he opened the gate and led me within the palace. Again we passed through myriad courtyards and burnished chambers, but it was different to my last visit: now none of it felt quite so magnificent as it had before. The splash of the fountains seemed quieter, the perfumes in the air less fragrant, the faces on those we met more tightly drawn.

I never saw Aelric speak to anyone, but Krysaphios was waiting for me. He stood where we had last met, in a colonnade lined with the marble heads of antique dynasties. His lips were thin with anger, and even before I had crossed the open square he met me with sharp words.

‘The Varangian captain swears you have done great mischief, Demetrios. You were hired to discover the Emperor’s would-be assassin, not hide him in the sanctuary of a monastery. If, indeed, this barbarian catamite is truly the one we seek.’

I had had enough of this sort of talk for one day. Without deigning to reply, I pulled the sacking from my bundle, lifted it to my shoulder and pressed on the lever. The eunuch’s eyes widened in terror as he guessed my purpose; he prostrated himself on the floor in an undignified sprawl, as – with a humming crack – the bolt from my weapon sprang into the air. It went many paces wide of him and struck a bust, shattering the stone face into countless broken fragments.

I could hear the running footsteps of guards behind me, but I had made my point. I lowered the weapon, and spread my arms wide in innocence.

Krysaphios raised himself to his feet, his shimmering robes creased and streaked with dust, his golden hat knocked crooked. His smooth face was ridged with fury.

‘Do you presume to enter this sacred place and murder me?’ he shrieked. ‘Shall I have you chained in the dungeons, for the torturers to tear you apart inch from inch? How dare you aim such a weapon at me, I who sleep at the feet of Emperors and guide the fate of nations? You might as well turn it on my master himself.’

‘Did you shit yourself?’ I had intended my antic to get his attention, but now we were both beyond the control of our feelings. ‘This is the weapon which was turned on your master, which came within a hand’s breadth of breaking open his skull like that marble head. I, Demetrios, discovered it. Just as I discovered the boy who wielded it against the Emperor four days ago. If you think a barbarian berserker would have done so well, one who would sooner slice off men’s heads than hear their secrets, then employ him next time.’

I turned my back and looked to the bronze doors. A line of Varangians – not Sigurd, thank God – barred it, their axes raised before them. Suddenly I wondered if I had not made a terrible miscalculation.

‘Demetrios.’

Krysaphios’ call stilled me, but I kept my gaze away from him.

‘Demetrios.’

The timbre of his voice was moderated now; he seemed to have mastered his anger. Reluctantly, I turned to face him.

‘You cannot expect to shoot your bow at the parakoimomenos and see me laugh it off as a jest.’ He may have subdued the violence in his voice, but it still burned in his face.

I smiled a grim smile. ‘Believe me, eunuch – if I had shot my bow at you, you would have breath neither to laugh nor curse.’ I lifted a hand to quell his retort. ‘And nor would I, I know. I do not threaten you; I merely comment on the miraculous accuracy of this foreign weapon, this tzangra. And its awesome strength.’

Krysaphios looked to the shards of statue on the floor by his feet. ‘That was the Emperor’s mother,’ he chided me. ‘Carved from a relic of antiquity. He will be displeased.’

‘He would be more displeased if it had been his head the arrow struck.’

I walked forward to Krysaphios and held the bow out for his inspection. It was an extraordinary weapon, much as the Genoese merchant had described it in the tavern, yet somehow more elegant and more lethal in form. Curved horns arced out like wings from the end of a shaft, which was carved at its butt to fit snug in a man’s shoulder. There was a channel routed down the middle to grip the short arrow, and a levered hook behind it to hold the string taut. As I had discovered with my gourds that afternoon, it was wondrously easy to learn to aim it, but a wrench on the shoulders to nock the bowstring. No wonder the assassin had only been able to loose one shot.

‘And you found this with the boy?’ Krysaphios plucked at the string, but could scarcely move it. ‘Sigurd did not tell me that.’

‘The boy had hidden it near the harbour. He told me where it was and I retrieved it.’ What he had really told me, at least at first, was that he had thrown it into the sea, but I refused to accept that he would discard so priceless a weapon. ‘He calls it an arbalest.’

‘And how did he come by it?’ Krysaphios’ tone was urgent now; he paced the tiled floor restlessly, kicking at bits of the broken statue with his toe.

‘The boy spoke only Frankish; I had his story through an interpreter. There were many things she did not understand, or could not make understood, but I think I have the bones of his story. He came here as a pilgrim some time ago; with his parents, I think, though they are dead now. After their death he survived in the slums by thieving and begging as he could. Then, a month back, a man found him and offered gold to accompany him. He was led to a meeting with a monk, who took him with four Bulgar mercenaries to a villa deep in the forest. For two weeks there the monk trained him in the use of the arbalest – as you have seen, it takes to men’s hands with miraculous ease. When they returned, he was told to climb atop a building on the Mesi and murder the Emperor as he passed. Yesterday he received a message that he should collect his payment by a certain fountain, but as he arrived he was attacked by a Bulgar and almost killed. There we found him.’

‘Why the boy? Why use him for this task when four stout mercenaries were at hand? Surely they would have been more suited to wielding this weapon?’

I had pondered the same question through the afternoon. ‘There are places a boy can go unnoticed where full-grown men would be challenged. Many children played on the roof of the carver’s house – one other making his way there would have aroused no suspicion. And after the event, he would have been easier to be rid of.’

Krysaphios seemed satisfied with my theory, though he said nothing. Instead, he raised a finger on his right hand and a slave appeared from behind a column.

‘Send word to the gaoler. Tell him to extract from the Bulgar prisoner everything he knows of the boy; also the location of this villa in the forest where he was trained. It may be that this foreign monk still has business there.’ The slave bowed low and ran off, and Krysaphios turned back to me. ‘Did the boy describe the monk?’

‘He said he had dark hair, like mine, but tonsured. His nose was crooked, as if he had once brawled, but the rest of his features were square and harsh. He said they spoke the same tongue. I did not press him more, for he was still weak from his wounds. I thought there would be time for that later.’

‘Less time than you think.’ Krysaphios folded his arms. ‘A great danger is approaching our city, Demetrios, and when it breaks over us we will need all our strength to defy it. If we do not find this monk within the fortnight, he may work a mischief that will ruin us all. The Emperor is the head atop the body of our nation, and if he is gone we are merely a carcass before carrion.’

‘What danger?’ Krysaphios had spoken almost as though the seven angels had sounded their trumpets, and the ten-horned beast was risen to engulf us. ‘Are the Normans coming again? I have not heard the armies assembled on the Hebdomon, nor seen the Emperor ride out to war. Surely if such a terrible danger was near, he would go to meet it, not invite it upon us?’

‘The nature of the threat, and how the Emperor forestalls it, are not your concern,’ said Krysaphios darkly. ‘You should address yourself to finding those who would kill him.’

‘I have.’ No eunuch was going to unsettle me with dire mutterings, and I have ever bridled at being told I am unworthy of knowing tantalising secrets. That, perhaps, is why I took up my profession. ‘I have found the boy who would have played the assassin, and the weapon he used in the attempt. By doing it so promptly, I have even saved your purse a little.’

‘My purse is deep enough. And do you really think you have succeeded, by finding a frightened boy and his barbarian plaything? What of the monk? Do you think this was a mere whim of his, and that having failed he will now trudge back to Frankia? He had money enough to buy four bodyguards, a villa and this marvellous weapon – did he collect that from alms-givers? And what would he profit from the death of the Emperor? Someone must have supplied him the money – someone who would gain much if the throne was empty. Someone who is unlikely to change his mind because his first attempt failed.’ He snorted. ‘You have not discovered anything, Demetrios: you have but picked up the first link in a long and tangled chain. Will your pride allow you to drop it so soon?’

He may have had a woman’s voice and a cripple’s body, but his mind and tongue were those of a serpent. And he knew men’s hearts: I would not give up his commission, for I saw as well as he that it was barely started. To claim success now would be to mimic the physician who removed the leper’s arm and declared him cured. But I would not concede that too easily.

‘If I am to continue, I will need certain accommodations. The Varangians must obey me when they accompany me. The boy must be left in the care of the doctor at the monastery where he currently lies: our chain may be twisted, but he is the only link we hold and it is a fragile link. And you must confide in me . . .’

I broke off as a slave came running out of the shadows, the same slave whom Krysaphios had sent to the dungeon. He did not defer or hesitate, but fell to his knees immediately before the eunuch.

‘Mercy, Lord,’ he stammered, before even given leave to speak. ‘The gaoler has opened the Bulgar’s cell. He is dead.’

‘The blood is hard,’ I said. ‘This was done some hours ago, maybe even last night. Has no-one been in here since then?’

‘He was to go without food all day. To spur his appetite for answering questions.’ Not even this horror could take the sting completely from Krysaphios’ voice.

‘No-one entered after your lordship left him,’ said the gaoler. And the Varangians guarded him all night.

I turned to Krysaphios. ‘It seems you were the last one to see him alive, then. After Sigurd and I had left for the monastery.’

‘Not the last, Demetrios.’ The eunuch’s eyes were cold. ‘Surely a man of your powers can see that unless he was a most accomplished acrobat, the Bulgar did not do this to himself. And the weapon which did this is gone. Whatever you say to the contrary, gaoler, someone has been in here.’

‘Someone who wanted to ensure that the Bulgar could betray no more secrets,’ I agreed. ‘And someone who wanted to send us a message.’

‘A message? Other than that he wanted the Bulgar’s silence?’ Krysaphios was impatient.

‘A message that the palace is no defence, that he – whoever he is – can strike wherever he pleases. If he had wanted to do it in stealth, he could have taken the Bulgar down from his chains and left the knife beside him, to make it seem he had killed himself. Whoever did this walked in under the eyes of the guards. And wants us to know he can do so again.’

Krysaphios turned to the Varangian who stood in the doorway. ‘Find your captain and have him double the Emperor’s guard tonight. Then search the palace grounds – it may be that this assassin is still hiding in our midst.’

I had my doubts, but kept them silent. ‘What about the boy?’ I prompted. ‘If our enemies feared for what the Bulgar might reveal, how much more must they worry about the boy?’

‘Sigurd is keeping the watch at the monastery, and has more men than he needs for the task. You may join him if you wish.’ Krysaphios moved towards the low-arched door. ‘I must tend to the Emperor.’

‘I will go home.’ It had been two days since I had seen my daughters, and though there had been other nights when I did not return, it always troubled them. And me. ‘Tomorrow I will see what further mysteries the boy can reveal.’

‘If he lives. Remember, Demetrios, we do not have much time to untangle this conspiracy. Two weeks before the danger is upon us.’ Krysaphios gave the dangling body a final, searching look. ‘Perhaps even less.’

Still I did not know what looming evil might force this urgency. But if it could draw such a tremor into the voice of Krysaphios, the eunuch who slept beside Emperors and guided nations, then I knew that I, too, feared it.