First I heard about them was on the 21st of July 2023.

I just started my training as Gestapo officer, a profession I was eager to learn and worked hard for. As everyone else in Germania I was in the Hitler Youth before I joined first the army and then had to learn a trade.
          There were no rumours anymore, they simply told us.
          We were sitting in the classroom for general politics, history and loyalty. Around me exactly 29 others like me, starting their career as policemen. The desks had workstations like the other classrooms, too and the walls were covered with a picture, a portrait indeed, of the Führer, re-founder of our glorious nation, several maps from different times and several pictures of skulls of the different races.
          Teacher Schmidt, a tall blond Major of the SS in retirement, held the gphl classes this semester for. This school was more an university than a school, the “Hochschule für Politfragen und Kontrolle” Germania (City). The students lived, ate, trained and studied in this building complex for at least four years and then either passed the test to become an Gestapo Officer or failed and could retry some of the tests.
          The history classes were the easiest ones for us usually. They had told us over and over again how our great-grandparents crushed first Poland, then France and then the Soviet Union. We knew the stories about the flight of Hess to Great Britain and operation Sea Lion to end the British Empire.
          We also knew about the terrible first nuclear strike the Americans executed on Nagasaki and Hiroshima. The Reich answered this by turning New York, Washington DC, Boston and Philadelphia into radiated piles of carbon.
          The Americans hadn't realised that our submarines were carrying V3 for about a year at that point. We would have never used this weapons first of course. But we had to be prepared and the underhandedness and cruelty of the american regime showed it's true face in these fatefull days.
          Of course that means the United States had to stop existing after their capitulation. The leadership of the Reich showed great wisdom by splitting the vast US into manageble and docile smaller states. That made it of course easier to segregate the different races in the new states. The southern states were made into a productive agrarian powerhouse. The north-east with its mainly white population produced fine automobiles, engines, planes and electronics for decades. The far and sunny west still serves us for cheap holidays.
          Schmidt kept blabbering on about the great success of the Africa campaigns and the reordering of the middle east and central asia. All things he explained well, but were not really of interest if you weren't to go there to work for some kind of government branch that was monitoring client state of ours.
          I played with the thought to turn on the computer for a moment, but every action while surfing the Weltnetz was monitored by the great shieldwall of ours. It had became a great tool to find insurgents. Nobody but the technicians and some high ranked party members knew about. There even were rumours about an artificial intelligence behind the entire network and it's monitoring.
          And that was crucial as it turned out.
~ “We have been infiltrated for years”, Schmidt said suddenly. The class murmured as the teacher looked each and every single one of us into the eyes.
~ “I am serious, gentlemen. I know that some of you weren't listening, as always and I am sure it will show in the tests, but this is important.”
          He turned on the beamer and started the video, directly streamed, encoded and in 4k showing something humanoid.
~ “This is G1, meaning Gefahr 1. This codename was assigned to this race of creatures.”, he said as the video showed two SS men from the ethnic purity division torturing and probing the apparently alien creature.
          Schmidt pointed on the different parts of the creatures bodies, assuring that those were indeed vital parts full of nerve endings and that the medical tests on humans in the last decades really had paid of.
          The creature had been taken after accessing a government network unauthorised and continued hacking into the machine leading the inspection and surveillance team of that node to file an electronic report, tracing the signal and dispatching the SS.
          Of course the inspection and surveillance team, in this case the team of 'Southern Bavaria, Schonhau, West' was observed by their node neighbours and their superiors, making the electronic control a panoptican system.
          On top of that three human unwilling collaborators had ratted even more G1 out. The Gestapo and the men from the ethnic purity division had a field day. Only one infiltrator successfully 'got away' by self destructing his personal weapon, leveling half a city block of downtown Milan in the process.

That happened all in 2017. I was still in school in 2017. The last six years the science department had used to research, explore, blueprint and replicate alien technology. This was not public knowledge yet. The Reichs highest brass and clerks, functionaries and the chancellor himself fear repercussions from the non-arian population, especially the chinese under japanese rule and the negroes in Africa. Species G1 was clearly hostile or it would have made contact, but the lower races might see their chance to topple the world order and bring a new degenerate age upon Earth.

~ “I am sure,” Major Schmidt said, “that they will tell the public about these … abominations, as soon as we jump our anti-matter warheads into the planetary crust of their home planet. All live and in 4k.”
He looked at his watch and added: “That will be in about two weeks.”