This is a story about two young men from Birmingham, UK, and it happened in the year 1969. I'm not claiming that this is exactly how it happened down to the last detail, but still, this is (more or less) a true story.
Terence, a man from the working class, around the age of 20, had been interested in the occult for some time back then. He had painted his room in matte black and decorated it with inverted crosses, pentagrams, and various pictures of demons and Satan himself. He read and wrote about dark cults, the supernatural and about everything that is evil and unholy.
His mate, John, knew this well; when he stumbled upon a book that was obviously written at least a couple hundreds of years ago - in Latin he went straight to Terence and gave it to him as a present. None of them had any idea what it was about, since they did not understand Latin - but it was obvious from the appearance and the sound of some of the words written in it, that it had to have something to do with black magic or witchcraft.
Terence was so amazed by this book that he forgot to ask John where he had found it. He spent the whole evening trying to figure what this book could teach him, but even after a couple of hours of intense studying, he still could not find a clue. Frustrated and exhausted, he put the book on his desk and simply went to sleep.
He awakened in the middle of the night, not sure what it was that had interrupted his deep slumber. And then he saw it.
On the end of his bed, barely visible in the dark of his room, stood an enormous black shape with fiery red eyes. And it pointed at him.
His natural reaction was to switch on the light, which he did - and the thing was gone. And as it turned out, so was the book John had given him. He looked for it everywhere in his room, in his house, at his friend house - but the book had simply vanished.
Of course, this incident left had a big influence on both of them. The influence was so big in fact, that they decided to write a song about it and later rename the rock band they played in after this song. The song's title was "Black Sabbath." And that is how Heavy Metal was invented.