Beginning in 1925 on a Montana cattle ranch, the story takes its time unwinding in five parts over an unspecified number of years. Straight-laced, shy George Burbank (Plemons), is the ranch owner. His brother, Phil (Cumberbatch) wants nothing more than to be a ranch hand. He is George's opposite, threatening, cruel, abusive. George's wife, Rose (Dunst) is the target of Phil's harshest insults. Peter (Smit-McPhee) is Rose's teen-age son from a previous marriage, haunted by his alcoholic father's suicide, and having trouble finding his place among the rowdy ranch hands. "The Power of the Dog" is from a line in the Book of Psalms in the Bible.
This movie takes patience on the part of viewers. Fine acting all around, great photography and scenery, but slow-paced with minimal dialog and long, silent pauses. It may not be to everyone's taste. Personally, I thought it was superb movie-making. Tension slowly builds throughout the movie. Where does this end?
You may find the ending puzzling. Pay close attention to Peter's voice-over at the very beginning. It's a clue. Keep it in mind for the next two hours and eight minutes. The movie has had limited release in theaters and can currently be seen on TV on Netflix.