A peripeteia is a point at which a major change occurs, especially a plot twist in a book. Most plays, movies, and novels include a peripeteia that keeps the reader or audience interested in the story.
In the fairy tale "Hansel and Gretel," the moment when the witch reveals herself to be evil, rather than a kind old woman living in a house made of candy, is a classic peripeteia. The twist in the story provides an exciting conflict for the main characters and keeps the reader on the edge of their seat. Peripeteia is a Greek word that means "a turn right about" or "a sudden change," from peri, "around" and piptein, "to fall."