The Hero's Journey model describes a character's transformation over the course of a narrative. It involves a protagonist who begins in their ordinary world but receives a call to adventure that prompts them to face an ordeal. They may first resist this call but ultimately cross a threshold by accepting the call, after which they cannot turn back and must face various tests along the way. This journey culminates in a central ordeal or showdown before the hero receives a reward and returns home changed by what they learned.