Creepy stalker

today you were hanging out with a friend at a park having a good time when suddenly your friend noticed someone watching you two behind a tree umm...do you know that guy? her voice sounded calm but she was worried. a minute later she grabbed her stuff and left and so did you that guy is so weird....Let's run so he doesn't see us you two started running until a moment later you noticed that your friend was gone and the man that was watching you started chasing you, a knife in his right hand