Witness

I think this movie can be about a child who just happened to be at the wrong place at the wrong time. He witnessed a murder and the men who just did this action will try to take him out. The Amish kid and his mother will have to leave Philadelphia and go to the village where they're from to be safer. The detective I guess will protect them during this journey. He probably will be some kind of bodyguard. The muderers are following every lead they can to find the kid and the woman and both sides (the "bodyguard" and the three men) will do whatever it takes to fulfill their duty. I guess the other issue that the movie will deal with is the clash between the American culture and the Amish one since they are completely different. There will obviously be a love story between the kid's mother and the detective.