"The Dwarves dug too greedily and too deep. You know what they awoke in the darkness of Khazad-dum... shadow and flame." Saruman, The Fellowship of the Ring
Recently, I've been thinking about this line. It comes from fantasy, but your more often find this theme - digging too deep, climbing too high, exploring places man wasn't meant to be and finding things man wasn't meant to know - in horror, and sometimes Sci-Fi. (There can be a healthy crossover between horror and sci-fi, but that's a topic for another blog...)
Jason was watching a movie the other night about a Russian crew that discovered a fungal parasite in the Kola Superdeep Borehole. (I've seen at least two X-files episodes with similar themes to this film.) There's The Thing, where the "digging too deep" or "climbing too high" is more metaphorical - the the high southern latitudes of Antarctica, a scientific expedition discovers an inexplicable creature.
Digging too deep/flying too high can apply to outer space - how many films are there about encountering malevolent entities out in the far reaches of space, a place where man was not meant to go? There are stories and films about being too deep in caves, too deep under the ocean... the list goes on and on.
I think there are so many types of this story, so many takes on this mini-genre because there is a very thin line between fear and fascination. We are curious creatures. We want to know what's out there in the dark, beyond the safety of the campfire. We want to know what goes bump in the night... but we're also afraid of the dark. We're afraid of the things that go bump in the night.