I walked in to touch the man – or the image – perhaps it was an image, like Fexler’s data ghost, just more convincingly drawn. Something the Builders considered art? Invisible glass stopped my fingers. I couldn’t get close to the man. My hand slid across an unseen surface, cool and slick to the fingertips.

The cell proved large enough for me to edge around the forbidden area, stepping through the dust at the margins of the room. The man’s hand came into view, holding a complex piece of metalwork to his head, an iron tube projecting from it to touch his temple.

‘I know this.’ The oldest of my father’s books held pictures of objects similar to this one. ‘It’s a gun.’

Another step and I saw the face, captured in the instant, imagining the pain but not yet feeling it despite the plume of blood and brain and bone behind him.

‘Fexler!’ I’d found the man himself. Not the memory.

The view-ring showed only the room, with Fexler lit red by the light, as if all the time that red dot pulsing amid the Iberico Hills had been this time-locked circle.

I made another circuit around the tableaux. ‘You stopped time!’ I thought about it, then shrugged. They say the Builders could fly. Who knows which is the more difficult, the stopping of time or taking to the skies? I thought of the watch buried in my baggage on Balky’s back. A device of the ancients – perhaps if I stopped its hands turning I would stop time just as they had.

‘You brought me here, Fexler.’ I spoke to the man. ‘What do you want? I can’t fix you.’

Obviously I couldn’t fix him. What had Fexler’s ghost been thinking? The answer came easy enough. Jorg breaks things. Fexler didn’t send me to fix this – he sent me to end it.

Of course breaking things that are sealed away behind unbreakable glass can prove difficult. As the point of my knife slid over the invisible barrier I started to doubt the glass existed at all. It seemed clear that something had to stand between a space where time flowed and a space where it did not. Zeno’s paradoxes sprung to mind. The Greeks loved paradoxes. Maybe they used them as currency. In any case I made no headway.

I walked away, a slight tremble in me from the fever. In every other cell nothing whole survived. I guess that the device in the ceiling had stopped time and in doing so had stopped the process of its own decay.

Memory stole me back beneath Mount Honas. In the Builders’ halls I had seen the remains of many narrow pipes, most just faint traces of verdigris, some bedded in the stone, some running against walls, some so thin that they could only have been strands of wire. The histories have it that the secret fire of the Builders ran along such paths to wake their devices. My watch needed no such fire but perhaps a coiled spring would not suffice for such mechanisms as that which held Fexler. Certainly it had not unwound over all the centuries. Did the machine need to be fed to keep time stationary?

A slow and minute inspection of the walls revealed no sign of hidden paths bringing fire to the ceiling ring. It took an age of hunting the corridors to find something to support me so I could check the ceiling. In the end I found a collection of bottles, like wine bottles but clear and cylindrical and slender as my arm. Binding all nine of them side to side with my shirt I made a very precarious platform on which to stand. Of all the Builders’ artefacts only glass had seen off the years without loss.

From my shifting, clinking platform I discovered that the barrier which enclosed Fexler narrowed as it rose so that at the ceiling I could get to within an inch or so of the metal ring. I used my knife to jab at the stonework around it. Poor treatment for a good weapon, but I had spare blades stashed on Lesha’s horse if I ever got back to him, and nothing else to work with.

Once before, in Gelleth, I had driven a blade into some magic of the Builders, a spirit trapped behind glass in the room before the weapon hall. A shock had run through the sword and thrown me twitching to the floor. The memory made me have to steel myself for each scratch and jab as I scored a circle around the ceiling ring. My muscles remembered the shock and kept trying to refuse to dig out a chance at renewing the experience.

The Builder stone started to flake and powder under my attacks. It took an hour maybe, possibly a day. It felt like a day. Sweat ran down me in hot streams and my arm ached, growing weaker by the moment as arms do when used overhead for more than a few minutes. I jabbed and scored, scored and jabbed. Without warning a deafening bang exploded around me, the light went out, and I fell with glass shattering below.

And for the second time since climbing down the shaft I lay bruised and aching in the dark with broken glass embedded in my leg. My makeshift lantern must have been knocked over and doused when I fell. Instead of searching for it I held the view-ring to my eye. The ring showed me the cell in greenish tones, revealing almost as much detail as I might see in daylight. Fexler lay on the floor, sprawled at my feet, the gun still clutched in his outstretched hand, a wisp of smoke escaping the barrel. Around his head a black and spreading pool of blood.

‘Thank you.’ Fexler – my Fexler from Castle Morrow, a projection of white light – stood beside the corpse, watching the splayed limbs, face unreadable.

‘Fexler, good to see you,’ I said. And it was. Any company in such a place is welcome. I drew a deep breath, taking in the stink of chemicals and fire from the gun, the tang of blood. The Builder halls felt real at last.

‘Why all the silence and mystery?’ I edged through the glass and dust to set my back to a wall, in part for support, in part because it’s good practice.

‘The men of my time lived amongst wonders but they were made no differently from their forefathers who wore skins and ate raw meat in caves, or from their descendants who carry iron swords and live in ruins they can’t comprehend. In short they had the same instincts as any man. Would you trust a copy of yourself?’

‘So they set spells on you such that no data ghost could kill the person from whom they were copied?’ I asked.

‘So that no data echo could harm any human, or ask for them to be harmed, or take actions that might lead them to hurt. It has taken a thousand years of subtle manipulation, of twists and sleights of logic, for me even to reach the stage where I could point someone like you in this direction, Jorg.’

‘And why would you?’ My hand settled on the fallen oil flask. I gave it a swirl. Maybe a fifth of it remained.

‘Data echoes are not just forbidden from harming their original template. In fact whilst the person whose data created any particular echo still lives there are an enormous number of restrictions placed on that echo, for the convenience, privacy, and peace of mind of the person in question. In the world that I inhabit I have been very much a second class citizen for considerably longer than your empire has existed.’

‘In Castle Morrow?’ The world that he lives in?

A tight smile, quick and gone. ‘Imagine an ocean wider and deeper than all others, full of wonder and variety, and on the surface a thickness of ice broken only here and there. The echoes that the Builders left behind, “data ghosts” if that’s how you want to call us, we echoes swim in such an ocean and the places where we may be seen in this thin world of yours are like the holes in the ice where we can surface. We exist in the joined complexity of the Builders’ machinery, and in places such as the terminal at Morrow we may be seen.’