originally this film had a comedic theme.
the entire filming crew including the director had little experience at that time.

the script writer for the film used locales near his home.  

the original script had a creature instead of Emily.

the script writer never liked the film much after the director John Hancock changed it's
theme to a horror.

the composer taught Mariclare (Emily) songs for the film at his apartment.

the house used for the outside scenes is still standing.

the inside house scenes were shot in a historical mansion.

the fog scene with the house was unplanned and used.

the Canadian title for the film was "The Secret Beneath the Lake "

release date was August 6 1971.

the lake shots were done in the Fall, so the actors froze.
the director used personal experiences dipliced in the film.
eg: He grew up on a fruit farm, his father was a base player.
the inside scenes of the house were shot in a different home
than the outside.
the filming duration was 25 days.
the film had numerous titles, "Jessica", "The Satanists".
the house used for the interior scenes was built in 1913. the 14
bedrooms and 11 bathrooms were used as dressing rooms for the
filming company.
the hearse used in the film was also used to transport the actors to the
different filming locations
the ghostly image of Emily rising in the water was actually a mannequin obtained from a
local depatment store.
the mannequin was filled with ping pong balls and the arms were filled with cellophane to assist in
buoyancy with a styrofoam head.
the producer was inspired for the films storyline by a tale told to him about a local of New England during
WW 1 who cracked a code being flashed from a hill top to German U-boats in the Boston Harbour. Before
the authorities could investigate, the man flashing had been murdered. the concept of a town hostile
towards strangers intrigued the producer, inspiring him to create the base story line for the film.
for promoting the film, radio stations would play a message to women listening to prove that they were as brave
as any man by entering a writing contest explaining why they would not be afraid of the film. the winning writer
would be given the opportunity to sit through a midnight screening of the film alone in any theatre they chose.
The E.E. Dickinson Mansion, the house used for the interior scenes, was vacant at the time of filming as Mr.
Dickinson III had passed away and his wife moved into an adjacent house to the mansion.