Proxima (28 page)

‘You know, I wish I just had a
truck
.’

‘Yuri Eden?’

‘Like the rovers on Mars. A truck I could just
drive
. The number of conversations like this that I’ve had with you over the years—’

‘I can’t help it,’ the ColU said, sounding almost miserable. ‘I can’t constrain my curiosity. Nor should I. Until my understanding of this world is complete
enough—’

‘Just tell me.’

It paused, as if gathering its thoughts. ‘Yuri Eden, I have told you that life on this world is similar in its fundamentals to life on Earth, but not identical. I believe the two
biospheres may be linked by a panspermia process that operated at a very early date. The earliest days of life on Per Ardua might have been like the early days of Earth, a world of simple bacteria,
drawing their energy from chemical reactions in the rocks. But all the time much more energy, a hundred times as much, was available, washing down from the sky—’

‘Proxima light.’

‘Yes. The next step was the development of kinds of photosynthesis, creatures that could draw energy directly from that light. The new kind colonised the surface, while the older ones
survived, sinking deeper into the planet. And there they still reside in great reefs, in caverns, in porous rock and aquifers, dreaming unknowable dreams. Just as on Earth, life on Per Ardua is
actually dominated by the bugs in the deep layers, mass for mass. But on the surface, as photosynthesis evolved, ultimately oxygen was released as a byproduct.’

‘Like the green algae on Earth.’

‘Yes, Yuri Eden, this step, oxygen production, was evidently difficult to achieve; on Earth it occurred only once, and in fact came from the coupling of
two
older photosynthetic
processes. I have yet to fully understand the equivalent process on Per Ardua – it is necessarily different because the energy content of the light here is heavy in the infrared – but
it is evidently just as complex, just as unlikely to have happened.’

‘Yet it did happen.’

‘It did, and I have been able to date the event from traces in the Arduan genetic record: some two billion, seven hundred million years ago.’ It paused. When Yuri didn’t react
it went on, ‘The next great step in the emergence of Arduan life, again mirrored on Earth, was the development of a new kind of cell: a much more complex organism, a cell with a nucleus, a
cell with different kinds of mechanisms within a containing membrane. Of course the energy available from burning up all the oxygen concentrating in the air helped with that. Such complex cells are
the basis of all multicellular life, including you, including the builders. This was an information revolution, not a chemical one; these complicated creatures needed about a thousand times as much
genetic information to define them as their simpler predecessors.’

‘Another unlikely step.’

‘Yes. But again it occurred on both worlds. And on Per Ardua this came about some two billion years ago.’ Another pause. ‘Yuri, I am not sure you are grasping the significance
of—’

‘Just tell me the story,’ Yuri said. He stroked his daughter’s hair, growing sleepy himself.

‘Multicellular life emerged some time later – evidently another difficult step to take. Seaweeds first on Earth, like the lavers we imported to Per Ardua . . .’

The new camp was coming into view, the lake settling into the contours of its latest shoreline. Yuri saw builders busily working all around the lake’s edge, and smoke rising from
Mardina’s camp fire.

The ColU was still talking about ancient life. ‘Of all the great revolutions of life this is the easiest to identify on Earth because it left such clear traces in the fossil record. On Per
Ardua, of course, there is no fossil record to speak of. And yet—’

‘And yet you, through heroic efforts, have worked it out anyway.’

‘I’m just trying to explain, Yuri Eden.’

‘All right.’

‘Yes, I have seen traces of this event in the genes, and also in some fringe organisms that have survived on Per Ardua to this day. And – now this is the significant point, Yuri Eden
– I have established that all this occurred some five hundred and forty-two million years ago. Do you see? Do you see?’

‘See what?’ Beth sat up now, rubbing her eyes. ‘I smelled smoke in my dreams. I thought the ColU was on fire!’

‘No, honey, it’s just the camp fire.’ Yuri didn’t see the ColU’s point at all, he couldn’t care less about such abstractions, and as the unit rolled into the
camp the conversation was already fading from his mind. ‘Go find your Mom, sweetheart, and I’ll help the ColU get everything put away safely.’

M
ardina prepared lunch.

It was a kind of quick picnic assembled from chuno. This was a long-lasting paste you could make from potatoes by freezing, thawing, desiccating them – a smart trick from the Andes that
the ColU had taught them, and invaluable for their travelling phases, but the result was a greyish muck in appearance that Beth had always cordially hated. But today she was hungry after the long
journey back to the camp, and excited about the move. Certainly she didn’t want to sleep any more. They all had a peculiar mixture of tiredness and energy, Yuri thought, like they had gone on
vacation maybe.

They decided to take the rest of the day off, and go exploring. The ColU, after trying to speak to Mardina about its mysterious science conclusions, grumpily rolled away and began the process of
unpacking its last load from the old camp, including another tonne of terrestrial topsoil.

The family walked to the lake’s latest location, with Beth skipping ahead, and Mardina and Yuri side by side.

The ground in this country, away from the lake and the water courses, was as arid as they had ever experienced it. In fact, Yuri suspected the landscape was becoming drier, hotter, the further
south they travelled. Which made sense; the further south you went and the closer to the substellar point you reached, the further Proxima rose in the sky, and the more heat it delivered. Yuri
still had the map Lemmy had compiled from the colonists’ remembrances of the shuttle flight, before they’d all killed each other, and that showed concentric bands of climate and
vegetation types around the substellar. If they walked far enough, Yuri supposed, they would in the end reach true lifeless desert, surrounding the substellar point itself, which the ColU predicted
would be the site of a permanent storm system. Even before that, maybe there would come a point where the ground was no longer habitable for them at all. But they were following the builders, who
had evidently been going through this process for uncounted millennia, and Yuri and Mardina had decided to trust them – well, having followed the
jilla
this far, they had no
choice.

They came to the lake shore, a fringe of muddy ground with banks of new stems growing vigorously. The stems seemed to be self-seeding, but the colonists had observed the builders practising what
looked like simple agriculture to help the stems along, planting shoots, irrigating the mud with crude drainage ditches. The water itself was still turbulent and turbid, not yet having settled into
its new bowl. Around the shore of the lake Yuri could see builders working, setting up what looked like a nursery area with the outlines of domed shelters rising up from the debris – and
already assembling basic middens, in preparation presumably for the next move of the
jilla
.

But there was another area where builders, adults and children, had been herded in a huddle, surrounded by others that spun and whirled around them. One by one the prisoners were taken out to an
area where more builders pinned them down and, brutally, crudely, disarticulated them, taking away their constituent stems to one of the new midden heaps. It looked like a prison camp crossed with
an open-air operating theatre – or, perhaps, like some appallingly brutal schoolyard game being played out by stick puppets. The sound of the continuing murders was an eerie rustling, a
clatter of sticks, the scrape of sharpened stone on stem bark.

Yuri and Mardina gently guided Beth away from the scene. They had seen this many times before: it was the aftermath of a builder invasion, of conquest. There had been another community of
builders here, living in the formerly dry lake bed, happily feeding off the local springs and stems – before the
jilla
folk arrived, brutally evicted them, flooded their homeland,
and massacred any survivors.

Beth hadn’t yet worked this out. Now, luckily, she spotted the nursery and ran that way to see.

‘The same every time,’ Mardina said, looking back at the slaughter yard. ‘And I used to think the builders were cute . . .’

Yuri said, ‘They’re little wooden Nazis. Some day we’re going to have to explain all this to Beth, you know.’

‘Genocide in Toyland. There’s never going to be a good day to talk about that. Maybe you could tell her about your Heroic Generation at the same time. Give her some context.
It’s not just builders that behave this way.’

‘For the thousandth time, it wasn’t
my
. . .’

But of course she was only goading him, for the thousandth time. She asked, ‘What did the ColU want to talk to me about, by the way? Seemed very intense.’

‘Oh, one of its theories. Life on Per Ardua. It seems to have got a pretty good family tree for this world now. Lots of bragging about genetic comparisons and stuff. He’s identified
major revolutions in the story of life here.’

‘What revolutions?’

Yuri thought back. ‘Photosynthesis, I mean a fancy advanced kind that produced oxygen as a waste product. Then complex cells, with nuclei. Then plant and animal life. The ColU got worked
up about the dates it’s established for these events. Meant nothing much to me.’

‘What dates?’

He concentrated. ‘Photosynthesis two point seven billion years ago. The complex cells two billion years ago. And the animals – umm, five hundred and forty-two million years ago, I
think.’

Mardina stared at him.

Some distance away, at the fringe of the trodden mud around the new lake, Beth had found something worth shouting about. She jumped up and down, waving. ‘Mom! Dad! Come see!’

Mardina called, ‘OK, sweetie.’ They began to walk over. ‘Yuri – are you sure about those dates?’

He felt uncertain, now she pressed him. ‘Well, I think so.’

‘It’s just – I’m no expert, but I took terraforming modules during my ISF training, and we studied the history of Earth life, the key transitions. Yuri, the dates for the
similar events on Earth are: two point seven billion years, two billion years, and—’

He guessed, ‘Five hundred and forty-two million?’

‘Yeah. I mean the last particularly is pretty precise, from the fossil record on Earth.’

‘Mom! Dad!
Come see
, before it all gets trampled!’

Mardina said, ‘Life on two worlds separated by light years having a common sugar base – well, you can wave your hands about panspermia to justify that. But such a precise
coordination of the key dates of all those improbable events?’

‘What does it mean?’

‘Damned if I know.’

‘Mom! Dad!’
Beth, quite agitated, was almost screaming now.

And when Yuri and Mardina finally got there, at the edge of the pond’s muddy fringe, they could see immediately why.

Beth had found a human footprint.

T
he invitation from Earthshine reached Stef at her workstation in the UN kernel lab on the moon.

In a short, low-res holographic message – a cube showing his well-groomed head, his smiling middle-aged-politician-type face – the Core AI requested that she come visit him on Earth,
at what he called his ‘node’ in Paris. He said he had a matter to discuss of global importance, but specifically of interest to ‘you and your sister’. There was also an
avowal, in legal wording, that the AI would make no attempt to access the growing knowledge base on kernel physics during his meeting with the sisters. Without that avowal Stef supposed the message
would never have been allowed through the various layers of security that surrounded her, here at Verne.

A similar message, an attachment noted, had been sent to Penny on Mercury.

Stef shut down the hologram with a curt acknowledgement of receipt, and spent a full dome-day thinking it over. That was her way when faced with dilemmas she found difficult or personally
unpleasant, a way she’d developed of managing her own instincts over nearly thirty-six years of life. Let the news work its way through her conscious and subconscious mind, before formulating
a decision. She even slept on it.

For one thing there was the sheer time she would need to take out of her own programme. Right now Stef was in a work jag that she was reluctant to climb out of. Well, she was always in a work
jag. Seven years on from the Hatch’s first opening and the Penny incident – as she thought of it – explorations of the Hatch and investigations of its physical properties were
shedding some light on the complementary studies of the kernels that had been going on for decades now. It was a slow, painstaking process, and it was full of gaps. Stef had the feeling she had
been handed the two ends of a long chain of discovery, and she had a way to go before she worked her way from either end in towards the centre. But it was absorbing – there was more than a
lifetime’s work here for her and her colleagues, she was sure. And
that
was a pleasing thought, since it pushed the need to make any drastic decisions about her own future off beyond
the horizon.

Decisions such as about her relationship with her sister.

There was another reason for her to be wary about Earthshine’s note. She was actually working now with Penny. Her sister, who was on Mercury, was running direct experimentation on the
Hatch emplacement, trying to detect emissions of various exotic high-energy particles. Unlike some siblings, indeed some twins, the sisters worked well together, as a long string of academic
publications to their individual and joint credit from the beginning of their careers proved. In this particular project at this particular time Penny was the experimentalist, Stef the
theoretician, but on other projects in the past, the record showed, it had often been the other way around. They were flexible that way, with close but complementary skill sets.