It’s 2009 after extensive testing and fixing the LHC is finally switched on to do its thing. A wonderful achievement! Surely the borders of science will be pushed and some of the most fundamental questions will be answered. The first results are truly spectacular. But then something happens...
Many tiny black holes are created, as much as one per second. But no problem, they are unstable and vaporize within a tiny fraction of a second. This is all according to calculations anyway. But next something unexpected happens; against the odds one of those baby black holes is stable. It is there to stay! Nothing seems to happen though; it simply escapes the lab and slowly sinks to the centre of the Earth attracted by gravity. Nobody will probably notice.
After some time the black hole bumps into an obstacle like for example an electron. It greedily swallows the particle. The black hole becomes heavier and pulls in some more particles, and more, and more… The black hole becomes bigger and bigger and bigger until it sucks up the Earth’s core, the mantle and then the entire Earth. Oops.
Fortunately it takes the black hole probably hundreds of thousands of years to mature. All the time we need to evacuate the planet. The probability on something happening like described is considered "acceptable small".
I am going to watch the Black hole again;-)