He sees that neither of us has joined in and his laugh trails off. He looks between us.
‘But I was there myself,’ he exclaims, redundantly. ‘I didn’t hear anything.’
‘What were you doing?’
‘I’d gone to meet Alexander of Cyrene.’
I wait for him to notice the look I’m giving him. I wait for the penny to drop. It doesn’t take long.
‘No.’
Porfyrius looks stunned. He recoils, as if he’s felt the blow himself; he throws up his hands. Every movement’s overdone, like an actor on the stage. Though, like an actor, it seems natural when he does it.
‘Clubbed over the head,’ Symmachus adds.
All the life’s gone out of Porfyrius. He sits on the edge of the pond, his head in his hands. ‘He was alive and well when I left him.’
‘Why were you there?’
‘The Augustus had commissioned him to write some sort of history. I served twice as Prefect of Rome – perhaps you remember? – and he wanted to check some facts about my tenure.’
‘What sort of facts?’
‘The monuments Constantine erected. The arch the Senate dedicated to him. Small details.’
‘Did he seem frightened? Any hint of something worrying him?’
‘Of course not.’
‘Alexander’s secretary said he had a document case. Do you remember it?’
‘Yes … no …’ Porfyrius drops his head. ‘I don’t remember.’
I pull out the necklace Constantine gave me.
‘Do either of you recognise this?’
That forces them to look towards me, though they give nothing away. Both these men are so well schooled in the ways of court I could pull out their own mothers’ heads and neither one would flinch.
Porfyrius stands, and moves closer to examine it.
‘It reminds me of the Emperor’s monogram. But not quite.’
He’s right. Constantine’s monogram is an X superimposed on a P, thus: . The version in the necklace is subtly different, the two characters melded into one:
. I ought to have noticed straight away.
‘You didn’t see anyone at the library wearing this?’
Porfyrius shakes his head. Symmachus just scowls.
‘There were no women at the library,’ Porfyrius says.
‘But plenty of Christians.’ Symmachus is standing on the line where sun gives way to shadow. Half his face is bright as gold, the other half sunk in darkness. ‘Eusebius of Nicomedia. Asterius the Sophist. Any number of priests and hangers-on.’
‘Could a Christian have killed one of their own?’
It’s the first time I’ve heard Symmachus laugh. It’s not a pretty sound – like a quarry-saw cutting marble. When he’s finished, and hacked the phlegm from his throat, he says, ‘Can an owl catch mice? Porphyry the philosopher said it best: “The Christians are a confused and vicious sect.” Thirty years ago we were about to exterminate them. If I’d wanted to murder Alexander I could have done it then and been hailed a hero. Now the wheel has turned. They murdered their own god – what wouldn’t they do to keep their privileges?’
Another serrated burst of laughter. ‘They’re only Roman.’
VII
THE CITY STOOD on a hill at the junction of two rivers, with the square towers of the Minster looming from its highest point. High walls hemmed it in – walls which had repelled Picts, Vikings, Norsemen and Scots in their time, but which couldn’t resist the columns of traffic that now queued through the gates. On the facing bank, executive flats and smart chain restaurants occupied what had once been thriving wharves and warehouses.
The moment she got off the train from King’s Cross, Abby could feel the difference. London had been close and warm, the friction of ten million people rubbing together. Here, the cold made her blush. A fine mist left dew on her cheek, while clouds overhead promised heavier rain to come.
She left the station and entered the city where a roundabout breached the wall. A few gravestones from a long-lost churchyard waited outside, marooned by time and the ring road. A bridge and a hill brought her up to the great medieval cathedral, the Minster. It had been built to be bigger than the mind of man and was now, if anything, stranger, looming over the city like a visitor from an alien civilisation.
It was late in the season, but a few sightseers still clustered in front of it. A busker played ragtime on an open- faced piano; a man dressed as a Roman legionary tried to get tourists to photograph themselves with him. Behind them, mostly unnoticed, a green-bronze emperor lazed on a throne and contemplated the pommel of his broken sword.
The rain was getting harder. She wiped a drop from her forehead, and was surprised to feel how wet her hair was. Her body seemed to be drinking up the damp in the air.
