We all know the story. The babysitter gets the baby settled in for a good night's sleep, then something awful happens. Sometimes, it's a series of taunting phone calls asking if she's checked the children, calls that turn out to be from a man who was upstairs the whole time. Sometimes the bad guy breaks in and does horrible things to the babysitter. Sometimes, its just a tree branch banging against the window in the wind. These stories do not just pop up out of the ether, and sometimes they're inspired by a mystery that's gone unsolved for decades.