There was not much time left. The government were powerless. In fact, we were all powerless, but I had to do something. After all, it was my fault. I had made a fortune, with my DateTimeTonight toothpaste. Now I would spend it. Maybe nothing could be done, but at least I could warn the people of the future. If there ever were any.
I bought a million robots and set them working 24 hours a day, 7 days a week. Together, they were doing just one thing, carefully engraving the text of my warning onto titanium sheets, in all the languages of the earth. Surely then whoever found it would be able to read it, wherever they came from. I had a thousand drones distributing these sheets across the whole planet, scattering them far and wide, hiding them in caves and lakes, secreting them at the bottom of glaciers and the top of mountains, scattering them across the sands of many deserts. The robots even wrapped my message around the DNA of an innocuous bacteria that could last perhaps a billion years and aerosoled a hundred, trillion, trillion copies high into the atmosphere. The bacteria would fall to earth, for some future scientist to decode. I launched a rocket so that the robots could blast the warning in letters a mile high on the Moon. What more could I do?
At first, the toothpaste had seemed a great idea. A single session brushing your teeth and they were as white as white. The paste seamlessly filled any cavities and guaranteed they wouldn’t decay for years to come. Perfect for a date night. It tasted good too. The governments of the world took it over, put it in the water supplies and everyone was happy. Well except for the dentists, they were just left making braces for teenagers. Of course, no one knew then, the formula was also a perfect and permanent contraceptive. Now, the planet was literally flooded with the stuff, and humanity would be gone in a generation.
Maybe aliens will come to earth in the future. No doubt they’ll have teeth. I hope they’ll read my warning. DON’T DRINK THE WATER.