I dreamed that all the people of the world suffered a new evil. They all stumbled. The media in all countries showed images of people walking and suddenly stumbling for no apparent reason, like invisible things. Until a scientist discovered that, for reasons that he could not explain now, we were all stumbling over objects that had been there and were no longer there. In other words, we stumbled upon a kind of temporary trace left by the presence of all objects. Then a spectrograph was designed to be able to see those footprints and walk without stumbling but, of course, it was very expensive, and then only those who could pay could avoid stumbling, and the rest of us lived full of bruises and wounds from falling so much.