Strike

A factory walks out, and the owners answer with spies who dissolve into owls and foxes, then fire hoses, then the army. For most of its length it plays as satire, with fat shareholders squeezing lemons while they talk about crushing the strike and thieves living in barrels buried in the ground. That comedy is what makes the ending hit: Eisenstein cuts the massacre of the workers against a bull's throat being opened in a slaughterhouse, and holds on both longer than you want him to. It's the first feature to cut for argument rather than for story, and it still works on you the way it was built to.