Warning: the following transmission transcript is a classified document belonging to the United States military. Unauthorized possession of this document is illegal; any military personnel caught violating the terms of their clearance, by illegal distribution or otherwise, will immediately have their clearance revoked, and will be tried under courts-martial for transgression of the Uniform Code of Military Justice. Any unauthorized citizen in the United States found to be in possession of this document, or an unauthorized copy, may be subpoenaed for treason.

UCMJ, 64 Stat. 109, 10 U.S.C. §§ 801–946; 18 U.S. Code § 2381

My name is Dr. Damien Huxley. I am writing this letter on March 25, 2071.

Two weeks ago, you received a binary message which—accurately interpreted—predicted an event in your immediate future that was so unlikely that only a person from the future could have made such a ludicrous prediction with such acuity and then be proven correct about the exact nature of the event that occurred. For the sake of national security, I will not reiterate what happened, lest the information fall into the wrong hands. Today, I received your reply.

I am relieved that you were able to decipher my instructions on how to reply, and that you managed to bury the totem that would give us empirical evidence that the law of causality could not possibly be violated as per our understanding. Unfortunately, as expected, there is no evidence that the totem you buried was ever put there in my reality.

I am with a team of nanotechnology-assisted humans at a research facility you will know in your timeline as the Cheyenne Mountain nuclear bunker. Since time in our reality is of such critical importance, I will keep this as concise as possible while not trying to redact details that are critical for the survival of humanity in your reality.

The median temperature of Earth currently sits at an estimated -240 °C. If you think this was a result of humanity trying to reverse global warming by modifying our atmosphere, then you are gravely mistaken. Like endangered wildlife that succumbed to incidental changes of environment, humans in our reality have also become the victims of natural selection at the hands of pseudo-sentient entities. Over the past few months, almost all species of fauna and flora have been annihilated, save species such as the tardigrade. Even the various seed banks we have are inaccessible. Humans will soon join that list if we cannot quell the explosive growth of quantum nanotechnology, although I suspect our window of opportunity is severely limited.

I know, I know, you are most likely asking how this could happen. After all, surely we put checks and balances in place to ensure that the inevitable technological revolution brought upon us by the singularity would not run out of control. I can assure you that we did; however, once nanotechnology began to self-replicate, it devised a quantum substrate that required temperatures close to 0 Kelvin—absolute zero. Before we realised what had happened, we were powerless to stop its self-replication. It manifested itself exponentially until it had spread like an unstoppable virus on Earth and beyond, artificially using its own computational force to cool the surrounding molecules to allow it and its neighbouring quantum particles to thrive at optimal performance. It is estimated that there are less than 200,000 people on Earth, and the loss of biological life is unprecedented. All of these people, like us, are only alive because they have utilised thermo-bunkers, but their food supply is dwindling. The great dying has been classified technically as the Quantum Extinction Event.

We have known about the ability to transmit data back in time on a quantum level for a while now, but all attempts to transport living organisms back in time have proved futile. In the same way that past generations have tried to protect the interests of future ones by cutting down deforestation, maintaining the ozone layer, reducing reliance on fossil fuels, and the disarmament of nuclear states, we must extend the same courtesy to our past selves by sending this warning, even if humanity within our own reality will not be saved.

The time in which this message has been sent signifies a critical branch in technological progress. Please stand by for a new directive.