There was no part of getting into that musty old suit that Sunday could be said to have enjoyed. The suit was a poor fit in all the critical places (it felt as if it had been tailored for a portly child, not a woman) and being seventy years old, it did nothing to assist in the process of being worn. Without the complicity of Jitendra, Jonathan and Soya, she doubted she would have been able to put the hideous old thing on at all. Conversely, without them there, she probably wouldn't have had the nerve to keep trying. Each component of the suit, as it clicked into place, added to her sense of imprisonment and paralysis.

The suit was not functioning, in any accepted sense of the word. Its motive power-assist was dead, so it required all of Sunday's strength and determination to move it even slightly. The best she could manage was a ghoulish, mummylike shuffle, and the effort of that would soon tax her to exhaustion. Not that she could go very far anyway. Its cooling and air-recirculation systems were only barely operative, so it was as hot and stuffy as the inside of a sleeping bag. It had no independent internal power supply, but needed to be connected to the Aggregate by an energy umbilical. Only then could the suit feed power to the helmet, which had to be locked into place before it would boot-up and function. Sunday felt ready to be buried. The air circulator huffed and wheezed like an asthmatic dog. Caution indicators, blocked in red, were already illuminating the faceplate head-up display. Even before it had fully booted, the helmet knew that it was plugged into a piece of barely safe garbage, and it wasn't too happy about it.

*The current user is not recognised,' the helmet said, its waspish buzzing into her ears in Swahili. *Please identify yourself.'

With an assertiveness that rather surprised herself, she declared, *I am Sunday Akinya.'

The helmet went quiet for a few seconds, as if it was thinking things over. *Please state your relationship to Eunice Akinya.'

*I'm her granddaughter. I've come to Mars for this helmet. Please recognise my authority to wear it.'

*What brought you to Mars?'

She had to think about that, sensing that the suit might be looking for a very specific answer. *Something I found in Phobos,' she said, cautiously.

*What did you find in Phobos?'

*A painting.' She took a breath, feeling sweat prickle her forehead. *A mural. There was a mistake . . . an alteration. The peacock should have been a different bird. A crane, maybe an ibis.'

*What brought you to Phobos?'

Had she passed the first test, or merely skipped to the next question having failed the first one? The suit gave no clue. *Pages from a book,' Sunday said, swallowing hard. *Gulliver's Travels. It was a clear reference to the moons of Mars, and Eunice had only ever spent time on Phobos, so that had to be the right moon.' Through the helmet glass, which was beginning to mist up, Jitendra and the others were watching her with avid interest. They were ready to spring to her aid should something go wrong with the life-support system, but knowing that didn't alleviate Sunday's sense of confinement. *I found the pages on the Moon a Earth's Moon,' she added. *In the crater Pythagoras.'

*What led you to Pythagoras?'

*A glove, which we found in a safe-deposit box, also on the Moon. The glove used to belong to Eunice Akinya. There were . . . gems in the glove. Plastic gems, three different colours. The numbers corresponded to a Pythagorean triple. Knowing Eunice's history, we were able to pinpoint a crash site in the crater.' She felt as if she was going to faint. *That's all I've got. The existence of the safe-deposit box came from an audit of Eunice's affairs, after her death.'

*What was the significance of the coloured gems?'

*The colours had . . . no significance.' But why would the helmet have asked her that if the answer was so simple? *Except they had to be different colours so that we could count them.'

That was what Jitendra had said, at least a and she'd been more than ready to accept that explanation. But the gems had been stuffed into different fingers. Given the care they'd taken with the examination, they'd have been unlikely to muddle them up.

*You have failed to pass all security questions,' the helmet said. *Nonetheless, you are recognised as having the necessary authority. Please wait.'

*Please wait for what?'

*Please wait.'

Even through the fogging glass, Jitendra must have seen the doubt in her eyes. He pushed his face close to the visor. *What's happening?' he asked, voice muffled as if many rooms away.

*It asked me a bunch of questions!' she shouted back, making herself feel lighter-headed in the process. *I failed at least one of them, but it's accepting me anyway. Can you crank up the cooling on this thing? It's like a Turkish bath in here.'

Jitendra and Jonathan exchanged words. Soya nodded and went to one side, out of Sunday's field of view. A moment later she felt knocking and tapping as Soya fiddled with the suit's backpack.

The faceplate continued to fog over, even as the air grew fractionally cooler than it had been before. Sunday wondered whether it was better to close her eyes than confront that misted-over glass only centimetres from her nose and mouth.

Then the mist began to clear. But just when the condensation had shrunk back almost completely around the faceplate's borders, it greyed over again. Sunday was about to call out to Jitendra when she realised the greyness wasn't more condensation; rather it had been caused by the head-up display obstructing her entire forward view. The head-up view was changing now, but the image that resolved wasn't the room inside the Aggregate.

What she could see was a broken aeroplane.

It lay upside down, snapped wings scissored across its fuselage. Dust had gathered in its lee. The plane slumped on the crest of a gently sloping ridge, bone-white against a horizon of darkening butterscotch. More dust spilt from the ruptured eye of its bubble canopy. Sunday thought of her brother, that this was some dire vision of the Cessna, crashed and upended. But this was not Geoffrey's aircraft.

To the right of the wreck, a hundred paces further up the shallow incline, sat a squat compound of pressure-tight huts. The huts' rib-sided shells had been scoured to a grey metal sheen by dust storms. Dust had also built up in their wind-shadows. Faded almost to illegibility was a hammer-and-sickle flag. A wind gauge, its cups as large as washbasins, whirred atop the roof of the largest hut.

Sunday found her point of view moving towards the aircraft. Acting independently of her volition, her line of sight dipped as if she was kneeling to peer into the inverted bulge of the shattered canopy. The seat was upside down, the buckled harness dangling open where it had been released. The cockpit was empty.

Her point of view turned from the aircraft, again without her direction, and approached the cluster of huts. The significance of the weather station and the smashed aeroplane was unavoidable. It was here, on the slopes of Pavonis Mons, that Eunice had landed and then sought shelter during a particularly ferocious storm. The plane had been intact when she brought it down, but had subsequently been plucked from its moorings by the winds, upended and crushed like a paper toy.

The station and the plane were gone now, but the documented fact of this episode had been the only thing pointing to a specific part of the terrain around the Martian volcano. Sunday already knew this. She could not have found the helmet without already making this connection.

So what did Eunice want with her now?

Metal steps, the lower treads buried in dust, led to the airlock in the largest of the Russian huts. The outer door and its interior counterpart were both open. Sunday's point of view ascended the steps.

Inside, it was brightly lit and wrong: physics and common sense were in dreamlike abeyance. It was not the interior of a Russian weather station on Mars but an annexe of the household. The light blazed in through square, thick-walled windows at a steep slant. It fell on recognisable furniture: chairs and tables, rugs and hangings, white-plastered walls. There were ornaments on the tables, dust-glints trembling in the air. In place of one wall, silk curtains billowed. Sunday would have been drawn to the curtains even if she'd had control of the suit's point of view.

A gloved hand reached out and parted the curtains. She pushed on through.

Outside it was Africa.

It was somewhere near dusk, some season when the skies held an abundance of clouds, gaudy with underlit colours: salmon-pink, vermilion, rare shades of rose and tangerine. Between the clouds, improbably, the slashes of clear sky were luminous cobalt. The trees, darkly silhouetted, reminded her of toy-theatre cut-outs.

The view tracked around. Kilimanjaro slid into sight, snowless. The household, blue-tiled and white-plastered, the walls reflecting sky in a hundred pastel combinations. A flight of cranes, like birds in a Chinese watercolour.

A stand of trees, more solid and real-looking than the silhouettes. Her point of view commenced towards that place of shelter. And the woman who had been leaning with her back against one of the trees, sitting down as she read in the last light of some long-gone day, made to stand up, neither hurriedly, as if she had been disturbed, nor languidly, as if she had all the time in the world. As if this was simply the ordained moment.

The figure rested one hand on her hip. The other grasped the book she had been reading, resting against her thigh. She wore riding pants and boots, and a white blouse with the sleeves rolled up to bony elbows. The blouse looked very much like the one Soya had been wearing.

*Good evening, Sunday,' the woman said.

*How do you know my name?' Sunday asked, wondering what she was dealing with.

*You told me, just now, when you answered the helmet's questions. Do you understand what I am?'

*Not really.'

*When I buried this helmet on Mars, it was already forty years old. I had its systems upgraded as best I could, but there were still limitations to what could be achieved. You are not interacting with Eunice Akinya, rather with a very simple model of her, with a limited range of responses and a very restricted internal knowledge base. Don't go mistaking it for me.'

*So . . . this is you speaking now?'

*This is . . . an interactive recording, a message to you, whoever you may be. The sphinxware wouldn't have admitted you unless you'd uncovered the trail that led to this point, so the chances are excellent that you're a member of the family, or at least someone with close ties to it.'

*As you just said, I've told you who I am.'

*You have, and we shall proceed on that basis.' Eunice a the recording of Eunice a glanced down at the book she'd been reading. *Firstly, you've done well to come this far. That took resourcefulness. I trust there were no particular unpleasantnesses along the way?'

*You could have picked a better burial site on Mars.'

Eunice's eyes sharpened. *There were local difficulties?'

*This is the middle of the fucking Evolvarium, Grandmother.'

*I have no idea what you're talking about. Evol-what? Succinctly, please.'

*Other than burying your helmet in a minefield, you couldn't have picked a worse spot on Mars. This whole area, for a thousand kilometres in any direction, is a no-go zone. It's a place where self-replicating machines are allowed to run riot. They evolve through generations, fighting for survival. Every now and then that evolutionary process throws up some gimmick, some idea or gadget that someone can make money from outside the 'varium. The machines are dangerous, and the people who run the place don't take kindly to outsiders poking around. Our guide was killed out there, and Jitendra and I came close to dying as well.'

*I'm . . . sorry.' The contrition sounded genuine. *I meant you to be challenged, but not put in real peril. Still, I can't be held accountable for what happened to Mars after the burial.' Again there was that sharpening of her gaze. *It's an odd thing to happen, though. This is the only place like it on Mars?'

*I told you, you couldn't have picked a worse location.'

*Then that's strange. I'm not one for coincidences, Sunday. Not this kind, anyway. There must be an explanation.'

*You tell me.'

*I only know what I know. But how could my little adventure on Pavonis Mons have led to this?' She gave every impression of thinking about that, reopening the book and leafing through it, scratching her fingernail against the fine Bible-thin paper, even though her eyes were not on the close-printed text. *After I lost the aeroplane . . . but no.' A quick dismissive head-shake. *That can't be it.'

*What can't be what?'

*I had to take shelter while the storm raged. The Russian station was still airtight, and it had power and the basic amenities. But I couldn't stay there for ever. The wind had damaged the aircraft, but I still needed a way out.'

Sunday issued a terse, *Continue.'

As if Eunice needed permission.

*The Russians had left a lot of equipment in their station, some of it still semi-functional. Before landing, I'd scouted a number of abandoned facilities and assets in the area. If I could salvage some of that junk, I'd be able to keep myself alive longer. Batteries, air-scrubbers, that kind of thing. Maybe even rig up some kind of repair to the aircraft. But I couldn't go out there. My suit wasn't stormproof, and in any case it only had limited range. I couldn't have walked far enough to do any good.'

*So you were in deep shit.'

*Until I found the robots.' Eunice snapped the book shut again. *The Russians had left them behind, in one of the storage sheds. I'm not surprised: they were old, slow, their programming screwed. Still, I didn't need them to do much for me.' She smiled quickly, as if abashed at her own resourcefulness. *I . . . patched them together, fixed their programming as best I could. Took me eight days, but it kept my mind off the worst. Then I sent them out in different directions, running on maximum autonomy. I'd told them to locate anything that looked potentially useful and drag it back to me.'

*I guess it worked.'

*No a rescue came sooner than I anticipated. The storm cleared, and my people were able to get me out. As for the robots . . . I forgot about them. But they were still out there, running with my lashed-up programming. They were supposed to take care of themselves, and to act competitively if the need arose. Do you think . . . ?'

*Do I think you inadvertently created the Evolvarium? I'd say yes, if I wasn't worried that your ego might already be on the point of stellar collapse.'

Eunice dislodged a fly from her brow. *I've achieved enough by intent, without dwelling on the things I made happen by accident. Regardless, I'm truly sorry if circumstances were more complicated than I envisaged, but it appears you weathered the adversity. Congratulations, Sunday. You've come through very well.'

*My brother and I have been sharing the burden.'

*And does that mean you have the full authority of the family behind you?'

*I wouldn't go that far, no.'

*I never counted on it. The important thing is that you've demonstrated the necessary insight and determination to make it this far.' Eunice lifted her head to study the sun. *My internal clock tells me that more than sixty years have passed since the burial. Is that really the case?'

*Yes,' Sunday said. *And you've only just died. The reason I'm here is because of an audit the household ran just after your death.'

*A long time in anyone's book. How have things been, while I was gone?'

*With the family?'

*Everything. The world, the flesh and the devil. Us. Have we managed not to screw things up completely?'

*I'm here,' Sunday said. *That should tell you something, shouldn't it?'

*I was born in 2030,' Eunice said. *People told me it was the best and worst of times. To me it just seemed like the way of the world. Whether you're born with famine in your belly or a silver spoon in your mouth a it's always just the way things are, isn't it? You know no different. Later, I realised I was fortunate, extraordinarily so. Fortunate to have been born African, for one thing, in the right place at the right time. My mother and father always said we should make the best of things, so that's what we did. The world still had some catching up to do, mind. I grew up with the last wars ever fought on Earth. They never touched me directly, but no one could entirely escape their influence. Please tell me they were the last wars. I couldn't bear to think we'd slipped back to our bad old ways.'

*There haven't been any more wars, which is not to say things are perfect back on Earth. I tease my brother about it often enough. They still have police, armies and peacekeeping forces, the occasional border incident. But it's not like it used to be.'

*The Resource and Relocation crisis taught us to grow up,' Eunice said. *We were like a house full of squabbling children for most of our history. And then the house started burning down. We had to grow up fast or burn with it.'

*We did.'

*What is it like out there now? Have you seen much of the system?'

*Not much. I was born on Earth, but I've spent most of my adult life on the Moon. This is the first time I've ever been anywhere else.'

*You never had the means?'

*It's . . . complicated.' Sunday nodded at the book her interlocutor was holding. *Is that Gulliver's Travels?'

Eunice glanced absent-mindedly at the title. *Finnegans Wake,' she said. *I liked Swift when I was little. Maybe Gulliver turned me into an explorer. But this is . . . denser. I still haven't got the bottom of it. So many questions. You could spend a lifetime on it and still not understand it.' She flicked open a random page, frowned at something written there. *Who was Muster Mark? What do you suppose he wanted with three quarks?'

*I don't know.' Sunday was ready to leave the suit now. *What's this all about, Eunice? Why did you bury the helmet? Why are you asking me these things?'

*You disappoint me, Sunday. To have so much of the world ready for the taking, and to have seen so little of it. I thought wanderlust ran in our blood. I thought it was the fire that made us Akinyas.'

*You saw it all, and then you came back, a sad old woman with no interest in anything except money and power and lording it over the rest of us. Doesn't that suggest all that exploring was really just a waste of time?'

*It would, if it hadn't changed me.' The book's leather binding offered a creak of complaint as she shut it. *I've seen marvellous things, Sunday. I've looked back from the edge of the system and seen this planet, this Earth, reduced to a tiny dot of pale blue. I know what that feels like. To think that dot is where we came from, where we evolved out of the chaos and the dirt . . . to think that Africa is only a part of that dot, that the dot contains not just Africa, but all the other continents, the oceans and ice caps . . . under a kiss of atmosphere, like morning dew, soon to be boiled off in the day's heat. And I know what it feels like to imagine going further. To hold that incredible, dangerous thought in my mind, if only for an instant. To think: what if I don't go home? What if I just keep on travelling? Watching that pale-blue dot fall ever further away, until the darkness swallowed it and there was no turning back. Until Earth was just a blue memory.'

Sunday's scorn was overwhelming. *You never had the nerve.'

*Maybe not. But at least,' Eunice answered mildly, *I've stood on the edge of that cliff and thought about jumping.'

*I came to Mars. Isn't that adventurous enough for you?'

*You've only taken baby steps, child. But I can't fault your determination. After all, you found me.'

*Yes. And where has that got me?'

*To this point. And I'm not done with you yet. Not by a long mark. There's a choice that needs to be made, a difficult one, and in all conscience I just don't have the mental capacity to make it.'

*That's uncharacteristically modest of you.'

*Oh, I'm not talking about me. I'm talking about this thing I've become: this bundle of clanking routines stuffed into a hundred-year-old space helmet. That won't suffice, not when so much is at stake. That's why I'm going to leave matters in your hands. Return to Lunar space. Go to the Winter Palace, if it's still there.'