Think of it as the moment where the protagonist crosses a metaphorical threshold into a new phase of the story, where the stakes are raised, and the journey becomes more complex. The threshold event usually presents a turning point for the characters and pushes them to take action, make difficult decisions, or reassess their priorities and motivations.
For instance, in the movie "The Lord of the Rings: The Fellowship of the Ring," the threshold occurs when the Fellowship enters the Mines of Moria. This pivotal moment takes the story into a darker, more dangerous realm and sets them on a perilous journey through treacherous caves, where they face新たな challenges and encounter powerful forces that threaten their quest.
In summary, the threshold in a movie is the pivotal point where the narrative shifts, propelling the story into its second act and introducing a significant change in the character's journey and the trajectory of the plot.