The Only One Left is a 2023 murder mystery/horror novel by American author Todd Ritter, writing under the pen name Riley Sager.

The plot concerns a woman who takes a job caring for elderly invalid Lenora Hope, who was accused decades ago of murdering her parents and younger sister.

Kittredge "Kit" McDeere is a 30-something caregiver accused of fatally overdosing her mother, who was dying of painful stomach cancer.

The only job she can get is acting as a home health aide to Lenora Hope, an old woman who, like Kit, was once accused of murdering her family.

The job is open because the previous nurse, Mary Milton, disappeared one night the week prior, leaving all her things behind.

She meets the servants: housekeeper, Mrs. Baker, Archie, the cook, Jessie, the maid, and Carter, the groundskeeper.

Kit realizes that Lenora typed out her full story to Mary Milton, revealing an affair she had with a man named "Ricky."

The real Lenora bribed their family doctor to declare Virginia dead, thus receiving both girls' trust funds.

Her father, displeased with his daughter's hidden pregnancy and illegitimate child, pays off Ricky and sends the infant away with the real Mrs. Baker.

She leaves her sister hanging there, removing the chair to make the scene appear to be a murder rather than a suicide.

The police find her and she spends the next fifty years living as a mute paraplegic, damage inflicted by the hanging.

[1] Reviewers noted the strong influences of the Lizzie Borden incident,[2][3] Daphne du Maurier's novel Rebecca,[4][5] and Edgar Allan Poe's short story "The Fall of the House of Usher".

She wrote that the book had "Sager’s signature breakneck pace" but also pointed to plot twists that "stretch believability".