One of the throw away lines used to show just how wierd Chicago can be and to show just how blind the the ordinary folk are to it is the idea of the city disappearing for a period of at least on hour from satellite photos. Apparently, the ground was still there but instead of concrete and asphalt there was trees, grass and animals. Subtle questioning of the inhabitants shows that none of them have any memory of any thing odd happening at all during that period.
Wow! Here comes a Conspiracy X campaign! A misfit team of experts is gathered by the mundane government of the country to determine what has happened. The only clue they have comes from a comparision of the satellite photos taken immediately before and immediately after the disappearance. There are a couple of points of difference in the photos such as a building being in a slightly different location or a park having moved.
I can think of several possible backgrounds that have resulted in these events. (No, I’m not telling you what they are.)