The series of short stories that I'm writing will deal with vampires. The title itself will let the readers know that it deals with vampires. However, a vampire won't show up until pretty well into the first story. Up until that point, there's nothing supernatural and no horror. Should I add in some foreshadowing (such as my MC seeing news reports of unexplained murders around the city, etc.) to remind the readers that Something's Up, or is the "Gee, everything's so nice and siffy around here; whoa, holy crap, vampires are real; WTF?!" abrupt turn okay?