[The film""s story was based on a real-life crime in March of 1927 perpetrated by married Queens, NY housewife Ruth (Brown) Snyder and her lover, a 32 year-old corset salesman Judd Gray.Harry announced his plan to find an unknown, hidden object in the castle to defeat You-Know-Who.When he mentioned it had something to do with Ravenclaw, Luna Lovegood (Evanna Lynch) suggested it was Rowena Ravenclaw""s lost Diadem, or tiara-like crown.Originally, there was no plan for a film sequel.Back to the Future Part III (1990)d.Robert Zemeckis, 118 minutesFilm Plot SummaryThe film opened on the early Sunday morning of November 13, 1955 (the next day, from the previous film).All eyes are glued upon the lone figure, as he strides along the wooden sidewalk.The telegraph agent phones an individual named "Pete" about he stranger""s arrival.On the porch of the dusty hotel, the stranger is suspiciously confronted by Coley Trimble (Ernest Borgnine) and Hector David (Lee Marvin).