In Agnes Hahn, Agnes went to live with her great aunts Gert and Ella at the age of four. Gert is now deceased, and Ella is in a nursing home in the advanced stages of Alzheimer's. Agnes's life is mundane; her work at the animal shelter routine—until she is arrested for a string of unimaginably heinous murders. Driven by the opportunity to write a bestseller, reporter Jason Powers covers the killings and soon uncovers a tangle of Hahn family secrets including one about Agnes's mysterious twin sister. Just when Powers is breaking through Ella's dementia to put together the puzzle behind the carnage, Ella is murdered. Now motivated by the family's unanswered questions, Powers strives to discover the truth about Agnes, her aunts, and the mysteries that surround them. In Imola, after witnessing the horrific murder of her twin sister Lilin, Agnes Hahn developed a multiple personality disorder in the form of her dead sibling and was admitted to the Napa State Mental Institution, simply known as "Imola" to its residents. By controlling her sister's body, Lilin escapes from the institution and begins a killing spree throughout northern California. Calling on the lessons learned in her therapy sessions and with the support of investigative reporter Jason Powers, Agnes begins to challenge her maniacal sister. Wrestling with the secrets of her dark past and her persistent inner demon, Agnes finds herself in the ultimate battle to regain her life.