What the Dark Night Is
The moment before the climax when everything is lost: the protagonist has failed, their allies have scattered, and the lie or wound has reasserted itself completely. It is not a scene. It is a sequence. The dark night is the protagonist alone with the worst version of their false belief, with no external path forward and no external agent to rescue them. It is the story's lowest emotional point, and its function is to make the climax's choice meaningful: the only way the climax can carry weight is if the alternative, surrender to the lie, was genuinely available during the dark night.