Reading a number of reviews here that are not very kind, I almost decided to skip this one. But I thought I'd give it 20 to 30 minutes then abandon it if not invested. I am glad I did, it seems to me the negative reviews are from viewers who simply did not comprehend the whole story. And that includes the very last scene where everything is wrapped up. I found it to be a good movie and a worthwhile viewing. On DVD from my public library, my wife skipped.
Filmed entirely in New Zealand, so it doesn't look much like the setting, Montana ranch land. The central characters are two brothers old enough to remember their first cattle drive 25 years earlier, in 1900. They have polar opposite personalities. One (Cumberbatch) is smart and educated, perpetually grungy, and quick to throw criticisms at others. The other (Plemons) is kind and clean. When he brings home a wife (Dunst, real-life wife of Plemons) his brother taunts her in subtle ways and her young teen son picks up on it. The rest of the story is how the son works things out to save his mother who is depressed and has turned to drinking excessively.
This is not a movie for the impatient, or for those who don't pay attention to detail. If anyone wants to understand it in more detail do a search on "power of the dog psalm 22:30".
