Widower Henry McCarty and Wyatt, his son, live on an isolated farm in Oklahoma Territory at the start of the 20th century (1906). After Henry (the 'Old Henry' of the title of the movie) finds a lost horse with some blood on the saddle, Henry succeeds in finding the man who was riding the horse: severely injured, the man is named Curry. The story develops from there, with an inexorable chain of events unfolding, as Old Henry finds himself confronting a gang of extremely violent outlaws. In the process, the past of Old Henry is revealed.
Within the parameters of the genre, this is a little masterpiece (at 90 mins, taut, punchy and to the point, as reflected in Old Henry's way of speaking). There are no women at all in the story - only men. Rough and potentially violent men, in the middle of the Old West, which is still the Wild West. But the characters are not caricatures: they have depth and their interactions are on several levels, with very good dialogues. If you like Westerns, this feels like an old-school classic in the finest sense of the word. My only reservation would be that the lead actor doesn't quite look the part, but this is deliberate on the part of the director: there is more to Old Henry than meets the eye.