Shrinking humans down to a manageable size in order to battle "climate change". But what if it was done already in the recent past? Discoveries of giant skeletons that the Smithsonian and Vatican covers up from the known world. Giant doors that we could never open if we tried in many old buildings, with little doggy doors cut into it for us to pass through. Countless photos of giant people that still exist today, look at Shaq the basketball player.
Videos of little people surface as well as "fairies" with wings and all, so perhaps this is another race of beings?