The Dark Stairs  (English, Paperback, Byars Betsy)

Mystery is in Herculeah Jones’s blood. How could it not be, with a father on the police force and a mother who’s a private eye? So when Herculeah notices a man hanging around the "Dead Oaks" mansion, she can’t resist doing some investigating of her own. Legend has it the old estate was the site of a murder, and now it looks like there’s something even more nefarious going on. Can Herculeah crack the case before the mystery man closes in on her?