Battleship Potemkin

Sailors are served maggoty meat, refuse it, and are lined up under a tarpaulin to be shot. The mutiny carries the ship to Odessa, the city comes down to the harbour to mourn, and then the soldiers come down the steps. That sequence never happened as one continuous action and was never filmed as one: boots, a pram, a mother carrying her dead son back up toward the rifles, a woman's shattered pince-nez, each shot cut short so the massacre is assembled in your head. The last reel is the squadron sent to sink the Potemkin, and the whole film has been built to make you hold your breath for it.