The arrival of Jessie in a narrative often serves as a catalyst for change, introducing new dynamics and conflicts that propel the story forward. Jessie's presence can alter relationships between existing characters, reveal hidden aspects of the plot, or introduce new themes and challenges.

For example, if Jessie is a new character entering an established setting, their arrival might create tension or alliances, depending on their background and motivations. Jessie could also bring crucial information or skills that are essential for the protagonists to overcome obstacles. Alternatively, Jessie's arrival might serve as a mirror or foil to other characters, highlighting their strengths and weaknesses.

Overall, Jessie's introduction can shift the narrative direction, deepen character development, and add complexity to the story, making it more engaging and dynamic.