Opening to a scary story

In the story Frankenstein Mary Shelly opens the story  with letters from  a man named Robert Walton.  In Walton's letters he writes to his sister about his exploration of the northern sea.  In the third letter Walton states that he meets a stranger at a port. An Robert shows a interest in this stranger an the strangers life story. An the actually beginning of the story it is the stranger life story. If I were to write a scary novel I would open the novel up with the setting of the story an then what is the scary person or thing. Then what the situation is that this scary person or thing has come up an why it has come up.