The Shout

The Shout is an award-winning 1978 horror film directed by Jerzy Skolimowski and starring Alan Bates, John Hurt, Susannah York, and Tim Curry (as Robert Graves, whose short story is the basis of the movie). Bates is a traveler who has spent 18 years with the Australian Aborigines and has learned how to kill with a shout. He intrudes on a young couple, and the effect of his presence is devastating.

You can watch it online at this link. Here's a trailer:

Ferdy on Film says, "The Shout stands today as a lonely island in cinema, one of a handful of entries in the history of the cinefantastique that evokes vast possibilities with a spare, even abstract, method." The British Film Institute says, "Most effective of all, however, is the director’s strange and darkly magical portrayal of the English coastline in his 1978 film The Shout, which contains – among many other unique things – one of British cinema’s most unnerving examples of sound design."

Roger Ebert gave it 3 out of 4 stars and says, "What makes the movie terrifying is the way in which the outback magic is introduced so naturally into the placid fabric of village life." Rotten Tomatoes has a critics score of 82%.