A mystery is something you cannot elude or understand and that remains without answer.

We generally talk of mystery when we have no explanation to give to an event. Synonymous of strangeness, inexplicable, or enigma, mystery has always fascinated men by its improbable side that forces us to think and try to understand.

Already present in the Bible, mystery includes the great natural, supernatural and divine truths that surround us. This aspect of greatness, of forces that overstep our Cartesian minds, is the source of mystery itself.

Over the ages, mystery has become a source for leisure (magics), for skepticism -which led to extremism sometimes (witch hunt)- and even for an endless inspiration for the authors who have a fertile imagination. Almost all the detective stories and the thriller genre movies are based on mystery. Agatha Christie may be the most famous author of detective fictions, but we could also mention Patricia Cornwell or Mary Higgins Clark as other masters of the genre. For the cinema, let's remember the unforgettable master of suspense: Alfred Hitchcock!

Amidst the greatest mysteries we can think of, there is the case of the presence of humans on Earth, and the linked question: is there another form of life in the universe? For some, it is impossible that we are alone whereas others do not want to hear anything about it for there is no evidence. In any case, how to explain certain marks or clues left in nature like the crop circles in the wheat fields? How not to consider certain evidences some recounted about spaceships or UFO? The mystery remains unsolved.