For several days now, you've been thinking that someone is following you. This quiet creaking from time to time, whispering and heavy breathing. Not only on the street, but even at home when you're washing dishes, surfing the internet or sleeping. You've even started to think that you're going crazy. And then again...

Sitting on the couch, you heard this strange sound again. You quickly turned off the TV, listening carefully to finally calm your nerves by figuring out its source.