This film, which also screens opn 24th August, is in the BFI Passport to Cinema season.
Chicago Reader review:
By far the most underrated of Sam Peckinpah's films, this grim 1974 tale about a minor-league piano player in Mexico (Warren Oates) who sacrifices his love (Isela Vega) when he goes after a fortune as a bounty hunter is certainly one of the director's most personal and obsessive works—even comparable in some respects to Malcolm Lowry's Under the Volcano in its bottomless despair and bombastic self-hatred, as well as its rather ghoulish lyricism. (Critic Tom Milne has suggestively compared the labyrinthine plot to that of a gothic novel.) Oates has perhaps never been better, and a strong secondary cast—Vega, Gig Young, Robert Webber, Kris Kristofferson, Donnie Fritts, and Emilio Fernandez—is equally effective in etching Peckinpah's dark night of the soul.
Here and above is the trailer.