Rundown intricately weaves the tale of Jennifer Thayer, a sixteen-year-old whose emotional turbulence peaks during her summer break. Craving attention and sympathy, Jennifer concocts a false story of an attempted rape, ensnaring her family and friends in her web of manipulation. Consumed by envy towards her older sister Cassandra, who seems to excel effortlessly in every realm—beauty, intellect, and social grace—Jennifer longs for her parents' focus to shift from wedding preparations to her own plight. What begins as a mischievous ploy spirals into chaos, as Jennifer asserts she narrowly escaped the clutches of a serial rapist wanted by authorities in the San Francisco Bay area. Her narrative grows more elaborate as she recounts a harrowing struggle, claiming she fought off her assailant with valiant resolve.

Despite being lavished with material abundance, Jennifer’s wealthy parents fail to fill the void of her unremarkable, unfulfilled teenage life. In her quest for thrill, she weaves a deceitful saga that soon attracts the probing eyes of law enforcement, her fabrications multiplying with each retelling. Jennifer unwittingly becomes a pawn, further entangling herself as the police close in on a suspect.

When her mother confronts her about potential abuse, Jennifer swiftly denies any harm, leaving readers to grapple with the truth of her words. Her grasp on reality appears tenuous, reflected in her guarded reactions to shield herself and her family from scrutiny. As those around her shower her with concern, Jennifer’s self-worth crumbles, exposing her inner turmoil. She is plagued by the fear of her deception unraveling and feels increasingly estranged from her community.

The mounting weight of her lies and the guilt they spawn leaves Jennifer drained, both emotionally and physically, as she edges closer to a complete breakdown, aptly captured in the novel's title, Rundown. Through Cadnum's narrative, the murky waters of truth and deception are explored, illustrating how selfish choices can fracture lives. Jennifer envisions herself as the architect of a dramatic saga, yet finds the chaos she has sown slipping from her grasp, losing command over her life and those entangled within it.