Very few [horror] films can stand serious analysis, but one which does is Carl Theodor Dreyer's Vampyr.

Vampyr (also known as The Strange Adventures of David Gray) is the story of a haunted world. A story of the dark and of the evil that dwells there. A morality play in which good and bad do vigorous battle for the soul of an innocent. Vampyr is also the work of one of the few genuine stylists the cinema has yet produced. (p. 17)

[If] there is one thing which really comes over in Vampyr it is atmosphere: the malignant, decaying atmosphere of a community dominated by evil….

Vampyr is an odd, difficult film to respond to completely, so many things are left in mid-air, so many things are not so much mysterious as just plain baffling, but providing you are prepared to accept the film on its own particular terms...