Answer:
To be able to make a surprising ending in a story is the writer will twist the story by tricking the reader.
Example: From the romance genre with many points of view, it is an Arabian night story "The Three Apples". It began when a fisherman found a locked chest. The first twist starts when an open room is found and there is a corpse inside. The initial search for the killer failed, and around occurred when two men appeared, separately as the killer. The concise chain of events ends with the revelation that the killer becomes the slave of the investigator himself.