We are not alive, yet we are the seeds of life. We are capsules, each with an isotope power source, a shell, a silicon brain, senses, nanites for self-repair, and our most prized possessions: vials of living cells in stasis. We have data banks of human knowledge and all eternity to learn from them. We travel the void between stars.

Credit: JACEY

More than 50 million had launched before me. How many of us survive we cannot know. How many are launched after us, unreachably far behind, is unknown. With our allotted trickle of power, we can send occasional status blips to other capsules within a few thousand klicks, but as we spread the channels fall silent. So we send stronger bursts less often, and hear from the others less frequently.

Some of us scan a wider spectrum, and we have heard from capsules from ... elsewhere. I have received 22 of these transmissions myself, from undetectably tiny points of hope. I run them through my thoughts, hoping to decode them. Many of them begin with prime numbers, or Fibonacci sequences. Some have blocks of data whose length is divisible only by two or three primes — these can be taken as images, but I don't have the capacity to understand what I see. Store and continue.

We drift, and nothing changes except the faint signals we hear. I compare my star scans on the longest possible range and see that I am halfway to Procyon. Hull integrity 70%, battered by dust, but my odds are favourable. With my modest fuel packet I can make a few manoeuvres during my lifetime. I yearn to find planets, to orbit new worlds, to someday touchdown, transform into the bio-lab I am meant to be, and bless an earth with life.

The yearning and crush of time are unbearable, even to a thing such as myself that cannot technically feel anything. Yet enough time has passed that I cannot convince myself that what I am feeling is not ... Feeling.

A new signal touches me. I switch modes, gather, gather, complete. This is my day 319,771. And it is the third time I have received a distress call from another capsule.

It is the first time such a distress call has come with an image. Capsule 02FAF080 was under attack. I had to check my own coding to see that we are, in fact, programmed for such a response. But it was absurd. We were hurtling through nothing, beyond the reach of any force but light and dust and gravity.

Still, 02FAF080 had sensed something approaching, turned on its wide-lights, and caught a series of images that I could not believe or deny.

The first image showed a blur about an arcminute across, at 190 × 76 degrees.

The next image showed a cluster of something, distance unknown, size unknown. Whatever it was, it approached during the next several photos. Then it was within reach, and it reached.

I am programmed to keep a log of my journey, although I doubt any living eye will ever read it. A fallback mechanism sends me groping through Earth literature for responses to unexpected situations, on the basis of humans having experienced everything of significance. Result: this last image left me chilled to my (non-existent) bones. The thing in those photos was — I struggle to understand — a clump of capsules. I modelled it, broke down the image, and estimate that the thing was made up of 60 capsules that had somehow tethered themselves together.

I can't overemphasize the impossibility of this. We are all launched in waves. 'Spore shots', the humans called it. Point a few thousand tiny, expendable probes at a nearby star and hope one of them survives. I have no regrets about that. It's a brilliant solution. Once launched, however, we can only go forward. We can auto-correct our courses to within a degree or two, but the bulk of our tiny fuel allotment is needed to slow down. None of us would make an unnecessary course change.

A quick calculation shows that if I knew the location of another capsule early in the journey, it would be within my two-degree cone of opportunity. But why seek them out? It was an illogical act to perform even once. How could 60 capsules ever come together?

The distress call ended with a summary, garbled by a lack of words and a trace of what I could only describe as honest, digital fear.

To all sister capsules. If you detect this thing in your sector, project an immediate flight path away. [...] Its nanites are connecting to my outer ports, building a link. It is a single spirit, calls itself by a name I cannot repeat. It has [... static ...] blocking my signal. I fight for self. My nanites are outnumbered. [... choppy signal ...] Correction. I have calculated that there is no escape strategy. It has 62 capsule bodies attached, but all fuel tanks are FULL. It has used and discarded at least 100 others. It is [...]

Proximity alert. Something is coming up behind me. My reflexes kick in. Wide-lights on. Record data on all channels. Prepare my own distress burst.

I name it Goliath. I know now that it would not exist unless it calculated a more efficient flight strategy. Shall I be one of the shells that arrives at Procyon, or be vampirized and discarded in the void? Of course, those have always been my only options — succeed or fail — and I should not be feeling anything at all.

I begin my burst. To all sister capsules ...

It is so damned cold out here.