The characters and locations in the film come from four different stories by H.P. Lovecraft. 'The Thing on the Doorstep', 'The Call of Cthulhu', 'The Shadow over Innsmouth' and 'The Dunwich Horror'.
Many of the interior location shots were filmed at the disused Royal Canberra Hospital which was demolished just months after filming was completed. The Australian National University, Canberra doubled as Miskatonic University in the film.