Content Warning: This novel includes depictions of violence, gore, emotional abuse, opiate addiction, overdose, suicide, teen pregnancy, traumatic birth, forced familial separation, financial abuse, classism, sexism, and elder abuse.

The Only One Left opens with the first Interlude, a memoir written on a typewriter. The typist describes standing beside the cliff outside her family home, her nightgown covered in blood. As she listens to the sounds of her sister’s screams, she throws a bloodied knife over the edge and into the ocean.

In the present, it is the fall of 1983. Narrator Kit McDeere returns to the office of Gurlain Home Health Aides to accept her first assignment after a six-month suspension without pay. A caregiver for the agency for 12 years without incident, Kit was devastated by the criminal investigation, ethical scrutiny, and public suspicion that led to her suspension. Now, Kit is aghast to learn that her new client is Lenora Hope, an infamous figure in the history of their small coastal Maine town. Lenora is suspected of murdering her parents and sister in 1929, when Lenora was 17; however, Lenora was never charged with the crime. Kit is reluctant to take the assignment, but Mr.