You Are Not Alone (2021) is a psychological thriller co-written by Greer Hendricks and Sarah Pekkanen. The story follows protagonist Shay Miller as she navigates a complicated series of events after witnessing a death by suicide in a subway station.

Shay cannot stop thinking about the woman who died in the subway, and she is taken in by the woman’s friends after attending her funeral. However, the charismatic women are not what they seem to be, and Shay soon finds herself caught in a dangerous game of cat-and-mouse. Through Shay’s story, Greer and Pekkanen explore The Dangers of Manipulation and Revenge, Loneliness and the Need for Connection, and The Importance of Self-Esteem.

The authors are known for crafting popular, suspenseful thrillers and have also co-authored three other books, The Wife Between Us (2018), An Anonymous Girl (2019), and The Golden Couple (2022).

This guide uses the 2021 paperback edition by St. Martin’s Publishing Group.

Content Warning: The source text and guide feature depictions of sexual assault, rape, domestic violence, animal cruelty, substance dependency, and death by suicide.

Plot Summary

Shay Miller witnesses a death by suicide in a subway station near her home. She and the woman lock eyes moments before the woman leaps to her death in front of an oncoming train. In the days after, Shay is unable to focus and increasingly fixates on who the woman might have been and what motivated her to die by suicide.

Shay learns from the detective investigating her death that the woman’s name was Amanda Evinger, and Shay begins learning as much as she can about her. After attending Amanda’s memorial service, Shay strikes up a friendship with Jane and Cassandra Moore, charismatic sisters who knew Amanda well. Shay finds herself powerfully drawn to Cassandra and Jane and ultimately comes to feel more interested in them than in Amanda. Shay does not realize that there is more to Cassandra and Jane than meets the eye: They organized Amanda’s memorial to gather information. They are worried that she spilled one of their secrets and, because they cannot pinpoint precisely how Shay knew Amanda, they are suspicious of Shay. They pretend to befriend her to keep an eye on her.

Cassandra and Jane are part of a close-knit group of women who share some dangerous secrets. In their circle is Daphne, the owner of a chic boutique and a sexual assault survivor; Beth, a public defender whose husband left her when she was diagnosed with cancer; and Stacey, a computer whiz with a troubled past. Lurking in the background is Valerie, a do-it-all employee who helps Cassandra and Jane with their dirty work. Unbeknownst to Shay, the women were recently involved in a murder: James Anders, the man who raped Daphne, was found dead on a park bench two months prior. Cassandra and Jane are worried that Amanda may have shared her knowledge of James’s murder with someone, and initially, they think that person might be Shay.

Shay is initially thrilled when Cassandra and Jane take her under their wing. They help her find a house-sitting job when she’s looking for a new apartment. They give her a stunning makeover that helps her to feel confident for the first time in years. They provide her with a social life, and she no longer feels quite so lonely. Not long after meeting them, she downloads a dating app and immediately matches with a potential new boyfriend. A headhunter reaches out to her on LinkedIn to offer her an appealing new job. Everything seems to be going well for Shay for the first time in her life.

As Shay’s story unfolds in the present, the novel flashes back to moments in Cassandra and Jane’s past and also provides glimpses into Amanda’s, Stacey’s, Valerie’s, Beth’s, and Daphne’s backgrounds. Through these flashbacks, it becomes evident that the Moore sisters are actually highly manipulative individuals. Their circle of friends metes out a particularly ruthless brand of vigilante justice. The sisters lure lonely women, like Shay, into their orbit by helping them solve problems and by becoming their primary sources of friendship and emotional support. They provide Stacey with legal assistance after an unfair arrest and then help her punish the serial child abuser whose assault she was arrested for. They help Beth to humiliate the man who divorced her when she was diagnosed with cancer. They murder Daphne’s rapist.

Shay does not initially suspect that anything is amiss with the sisters, although after a strange series of events, she begins to have doubts. She realizes that the makeover the sisters gave her makes her look exactly like Amanda Evinger. She finds an apartment online that turns out to have been Amanda’s studio, and with the blessing of the sisters, she moves in. She finds a mysterious package containing a bloody towel and a scalpel in Amanda’s old mailbox. One night, after Cassandra and Jane have come over for drinks, she wakes up groggy, suspecting that she has been drugged, to find the police in her apartment. The bloody towel and scalpel lie on the floor, along with a watch and wallet that she has never seen. She is taken to the police station for questioning. When she calls the sisters, they coldly tell her to stop stalking them.

Shay goes on a run, hoping to hide from the sisters while she figures out which crime they are framing her for and learns as much as possible about them. Through online sleuthing, Shay learns a shocking series of truths: Cassandra and Jane’s shadowy friend Valerie, whom Shay has met under several different aliases, is actually their sister. Daphne’s rapist, James Anders, is their former step-brother. He tried to rape Valerie when they were in high school, and the women have wanted to punish him ever since. When they happened upon Daphne’s name in his cell phone, they befriended her to help her (and themselves) “get rid” of James.

Shay realizes that she is being framed for James’s murder and that Valerie is the group’s true mastermind. Shay fends off Valerie’s attempt to kill her in a train station, shoving Valerie to her death in the path of an oncoming train. With the help of the police, she ensures that the Moore sisters and their circle will spend decades in jail for their crimes.