epiphany

A sudden realization or insight experienced by a character. This higher level of clarity might reveal the truth about a situation, but most often, an epiphany is a sudden insight into oneself. In fiction, the epiphany is a useful tool to mark a significant moment of change in a character; moreover, because an epiphany is sudden, the moment is usually a surprise twist in the story, making use of situational irony to involve the reader in a new level of understanding.