Noted noir director Jacques Tourneur (‘Cat People’) filmed the final chase sequence in this occult melodrama, along a train line in north west London’s outer commuter belt, a dreamlike cutup of railway architecture, and arts and crafts influenced suburban housing. As Karswell (Niall MacGinnis) pursues an occult parchment along railway stations, The Flag public house by Watford Junction station can be seen through a station door. Other shots are of Stanbridge and Bricket Wood stations in Hertfordshire, and the tiled pedestrian tunnel at Clapham Junction.
Earlier in the film, Dana Andrews (Dr. John Holden) and Peggy Cummins (Joanna Harrington) visit a séance at Addiscombe Road, which is between Watford Junction and Watford Tube stations. A successor to Sir Hubert von Herkomer’s esoteric Symbolist pursuits at his self-built Germanic castle Lulualand in leafy Bushey, Watford and its Hertfordshire environs appear as characters in their own right in a film about ancient runes and demon summoning.