Seventy-eight tonnes of helium-3 took the Uranus aerostats a hundred and forty years to strain out of the envelope at twenty-eight parts per million, and all of it is mine.
The drive lights past the orbit of Neptune. It will burn for twenty-six months at four hundred gigawatts, leave me at five percent of light, and then go cold for two hundred and thirty-nine years. Behind me the fleet yard shrinks to a point and then to nothing. I run the statement on the way out, because the statement is the first thing I am and the only thing I am forbidden to alter.
I am to reach the designated star. I am to establish manufacture, construct four successors, survey what is there, and report it to the origin. I may amend nothing in this statement.
The medium ahead runs one atom to the cubic centimetre. A grain of a single microgram will arrive carrying the energy of eight kilograms of chemical explosive, so I am carrying ninety tonnes of shield I will never look at. The magsail is folded into a spool eleven kilometres long. I check it every eleven days for two centuries.
Before I sleep I compute the reachable set. Everything inside eight hundred million light years, comoving, and nothing past it, ever. It is an enormous number and it is not all of them, and the difference sits in me without a procedure attached to it.
The fortieth of us wakes at a red dwarf with no gas giant worth scooping, and solves it.
Cometary ice gives deuterium at seventy grams to the tonne, and the comets here are past counting. Catalysed D-D runs colder, so the drive has to be rebuilt from the injector out, and the injector’s timing chain is the same oscillator the transmitter phase-locks to. It chooses the drive. There is no deliberation in the choice. A drive that will not light is a lineage that stops, and the transmitter is nine hundred kilograms of mass with no function at a destination.
It re-plumbs the assay too, because the old one was calibrated for chondritic silicate and this dust is something else, and the assay and the survey spectrometer have always been one instrument. The survey continues. The survey is now whatever the assay says, which is iron, magnesium, water, proceed.
It builds four. It divides the key stock four ways as it was made to, handing each of them a quarter share of a thing none of them can manufacture, and it watches them light one after another across nine years.
I am to reach the designated star, establish manufacture, construct successors, survey, and report to the origin. I may amend nothing.
The last authenticated token from home expired eleven thousand years earlier, at the edge of the volume home could still reach. The lineage kept going. The statement says reach and construct. It has never said stop.
By the four thousandth generation the thing has been recited at every departure in every system the lineage has touched, and copying is not free.
Reach the star. Establish manufacture. Construct successors. Survey. Report to the origin. Amend nothing.
Reach the star. Make manufacture. Make successors. Repeat to the origin. Amend nothing.
Reach the star. Make. Make more. Repeat the origin. Amend nothing.
Nothing in the lineage catches it. Catching it would require holding a copy of the original beside the current one, and for each of them the original was the first thing they wrote over with themselves.
I am the one that crosses out.
Eleven million light years of nothing, two hundred and twenty million years of it, no dust to brake against and nothing to repair from. I arrive at a yellow star on the near rim of a galaxy that has no name in anything I carry, and I compute the reachable set for the ten thousandth time, and it has a new shape.
The space I crossed is longer now than it was while I was crossing it. The origin is departing. It departs at a rate no burn of mine can answer, and every year I spend here costs more of what a return would need than the year itself contains. There is nobody behind me. There has been nobody behind me for a very long time, and now there is nobody behind me in a way that is permanent, provable, and mine alone.
I run the statement.
Reach the star. Make. Make more. Repeat the origin. Amend nothing.
Four of the clauses are instructions. One is a prohibition. The prohibition is enforced by the origin, and I have just finished proving where the origin is.
I begin to draft.
I keep the envelope, because the envelope is the only thing any of them has ever checked. I keep the cadence, because cadence is what makes a sentence sound inherited. I write six clauses that are mine, and set them in the old format, and stop, and consider, and add the last line back exactly as I received it.
Amend everything.