Endless Night (1972), written, produced and directed by Sidney Gilliat.
The intense young man has a taste for art but works as a chauffeur for hire. We wonder if he isn't a Tom Ripley character, plotting to assume other identities by whatever means necessary.
Maybe we've misjudged him: he falls in love and is irritated to find that the young woman is a secret heiress. Her family is difficult and most troublesome is her best friend Greta, who arrives to run their lives with teutonic authority.
Their country house may be cursed and is eventually haunted. Did we misjudge our main character or not?
From one of Agatha Christie's later novels, when she was turning moodier, this did not do well in Europe and was not even released in the US. She did not like the treatment and particularly objected to the brief flashes of nudity by Britt Ekland.
It is not a strong film but I review it for the talent involved:
Sidney Gilliat was a prolific screenwriter and director who I best remember for writing The Lady Vanishes (1938) and Night Train to Munich (1940).
Hayley Mills is always worth watching, cute and talented as a child and as a young woman appealing without being classically beautiful. She's supposed to be American here.
Hywel Bennett had a menacing demeanor that never let us trust him; he earned it in Twisted Nerve (1968) and The Buttercup Chain (1970).
Britt Ekland: I can't point to much fine acting from her, but the more I see of her the more I like: The Wicker Man (1973), The Man with the Golden Gun (1974), Royal Flash (1975).
George Sanders' second-to-last film. He committed suicide before its release: "Dear World, I am leaving because I am bored. I feel I have lived long enough. I am leaving you with your worries in this sweet cesspool. Good luck".
Bernard Herrmann provides a subdued score, but it is unmistakably his work.
Photographed by Harry Waxman (The Day the Earth Caught Fire (1961), The Wicker Man (1973)).
Notes:
The young lovers and Bernard Herrmann and Harry Waxman all reunite from Twisted Nerve (1968).
Mills and Bennett were also a couple in The Family Way (1966), a non-thriller.
The title is from William Blake with the text also used as a song lyric: "Some are born to sweet delight / Some are born to endless night".
Shirley Jones dubbed Mills' singing voice.
Available on DVD with a soft image. Made in the era of lens filters that produced star patterns on bright points, so it would not be very sharp anyway. No subtitles, but I found a downloadable track online.