Narrative tension in a story refers primarily to suspenseful uncertainty about the story’s outcome. It is the emotional energy that keeps readers engaged, as they anticipate how conflicts will resolve and what will happen next. This tension arises from various elements, including conflicts between characters, obstacles faced by protagonists, or the stakes involved in the narrative.
While the other elements mentioned—such as the basic situation, flashbacks, and foreshadowing—can contribute to the overall experience and development of a story, narrative tension specifically focuses on the suspense and uncertainty that drive the audience's emotional engagement and curiosity about the unfolding plot.