‘I’m sorry,’ Sunday and Jitendra said in unison. Then, on her own, Sunday continued, ‘And what was your side of the story, Jonathan? Why this secrecy? What persuaded Lizbet to keep it to herself?’
‘I know why your grandmother came back to Mars. My funeral was a useful pretext, but she’d have found a way to do it whatever happened. She spent time on Phobos, more than she needed to. I don’t know what she got up to there, but I presume whatever it was led you here?’
Sunday eyed Jitendra before proceeding. ‘We’ve been following something ever since she died. It began with an anomaly in her private banking files. That led us from Africa to the Moon. On the Moon my brother found something in a safe-deposit box. That led us to Pythagoras. What we found in Pythagoras led me to Phobos. Phobos led me to the Evolvarium.’
‘And now to me,’ Jonathan said.
‘Except I didn’t find you,’ Sunday said. ‘You found me. Soya knew I was on the planet: that’s why she contacted me in Crommelin.’
‘It was easy to track your arrival,’ Soya said. ‘Given the timing, there couldn’t be any other reason why you’d come to Mars, other than to find out what your grandmother had buried here.’
‘I failed,’ Sunday said.
Jonathan braced his hands on his knees and rose from his chair. ‘Do you have any idea where you are?’
‘Somewhere out in the sticks, I’m guessing. A camp or station everyone assumes to be unoccupied. Probably quite near the Evolvarium, since I doubt we travelled very far overnight.’ She was careful not to voice her suspicion that they were moving.
‘Not near,’ Jonathan corrected, with a smile. ‘In. We’ve never left it.’
It came back to her in disconnected glimpses, as of a dream forgotten until some chance association called it to mind, much later in the day. Jitendra had seen it first: that hill, a feature in the terrain that ought not to have been there, glimpsed from within their makeshift shelter as they waited for night and whatever it might bring. A hill that was approaching.
The Aggregate.
Not a hill, but a machine as large as a skyscraper, crunching slowly across the Evolvarium. Sunday remembered what she had learned regarding the Aggregate, aboard the Overfloater airship. It was not one machine, but a society of them. From the level of sifters to apex predators, they had organised in the interests of mutual reliance and interdependence. It was a stinging affront to the basic function of the Evolvarium. Whereas the other machines toiled and clashed and evolved, sparking off industrial novelties as a by-product of their struggle for survival, the Aggregate gave nothing back. Whatever it innovated, it kept to itself.
It had sent out an envoy to meet them. With that memory came the aftertaste of the fear they had both felt as they crouched in their makeshift shelter. The Aggregate’s envoy was a quick-scuttling thing like an iron ant, black- armoured and as large as the rover whose wreckage they had repurposed. Even if their suits had been working at full capacity, they could never have outrun it. It had ripped away the petals of their shelter, flinging them to the winds, and loomed over them in all its eyeless belligerence. Its head was a blank metal sphere, its torso a pinch- waisted cylinder. In addition to its pistoning black legs it had whipping cilia. It had plucked them from the ground, not without a certain carelessness, and a red-lit aperture had opened in its belly.
After that, Sunday didn’t remember very much.
Yet here they were, in the Aggregate. There was no need to take Jonathan Beza’s word for that. From a high vantage point, the queen of her own castle, Sunday was looking down on the very machine she had assumed meant to have her crushed and recycled for useful materials.
It was motley. Hundreds of basic organisms had fused or locked together to form the structural outline of the Aggregate, and that didn’t begin to touch the implied complexity of its interior. Not a skyscraper, then, for that conveyed entirely too much symmetry and orderliness. The Aggregate was more like a city block, a dense-packed huddle of buildings constructed at different times and according to varying objectives and governing aesthetics. It was approximately pyramidal in shape, wide and flat at the base, rising in steps and pinnacles and buttresses to a sort of summit, but there was nothing geometric or harmonious about it. Sunday saw where some of the machines had fused into the main mass, like gargoyles on a cathedral. Others must have changed beyond all recognition, so that it was not easy to tell where one began and another ended, or what their original forms and locomotive principles must have been like. From here, looking down, she couldn’t see how the Aggregate moved its colossal bulk. She presumed countless legs and feet were deployed under the flat base of the city, working in concert so that the ride was mostly smooth. Dust welled up constantly from the Aggregate’s margins, stirred by whatever mechanisms toiled underneath it.
‘No one ever mentioned anything about this thing being inhabited,’ Sunday said. They were in a many- windowed cupola, a hundred or more metres above the ground.
‘They don’t know,’ Jonathan said. ‘No one does, except Soya and me. Maybe some of the Overfloaters suspect, but that’s not the same thing as knowing and it’s certainly not something they’ll talk about in polite company. They can’t tell for sure, from the outside. The glass is one-way, and with all the waste heat and chemistry a machine like the Aggregate radiates, there’s no way of picking out the signatures of a couple of human occupants. Especially when the Aggregate doesn’t
‘So you’re its prisoners?’ she asked. But that didn’t work: Soya clearly had free roam of Mars, and must have come back here of her own volition.
‘No,’ Jonathan said. ‘I’m its client. The Aggregate benefits from a human consultant. That’s really all I am to it: just another modular component it can depend on when the need arrives. It makes me comfortable – more than comfortable, actually – and it tolerates my absence when I’m not here.’
‘It lets you come and go as you please?’
‘We agreed terms. It would rather put up with that than have me kill myself. Needless to say, I can’t go very far – that’s one of the drawbacks of being dead. But I’m not a prisoner.’
‘I’m finding all this a little difficult to take in. I’ve spent my whole life thinking you were dead.’
‘I’m afraid there was no other way. The best that Soya could do was warn you to be on your guard against the Pans. It was obvious to us that they couldn’t be trusted simply to let you walk away with the prize.’
‘You knew they were planning to steal it?’ Jitendra asked.
