In the novel, the tension of the story is also the tension of the story plot. I don't understand what this means.

Tension is originally a contradictory force produced by the friction of opposites or complements in physics. As a literary theory, it was put forward in the British and American New Criticism. In the new criticism, the concept of combining sensibility with rationality is discussed. Poetry contains connotation and extension, and the far-reaching appeal of the contradiction between connotation and extension is also tension.