The following version of this book was used to create the guide: Phillips, Jayne Anne. Night Watch. Alfred A. Knopf, 2023.

Jayne Anne Phillips's novel Night Watch spans the years from 1864 - 1883. Organized into four sections and an epilogue, the narrative alternates between the characters' past and present lives throughout. In order to enact the Civil War's effects on her characters' psyches, the author employs the past and present tenses and the first and third person points of view. For the sake of clarity, the following summary uses the present tense and a linear mode of explanation.

In 1861, Ephraim Connolly leaves home, enlists in the army, and joins the War effort. He abandons his given name and dons the nickname Sharpshooter instead. He is sad to say goodbye to his lover and wife, Eliza, but is devoted to the Union's effort. He tries to forget his past life in Virginia so as to survive the war. After his three-year enlistment ends, he reenlists, determined to see the War through. In 1864, he is severely injured during a battle.

Sharpshooter wakes up in an Alexandria hospital. His surgeon, Dr. O'Shea, informs him that he suffered a severe head wound, which he is still trying to repair. Sharpshooter has no memory of the War, nor of his life before it. With Dr. O'Shea's and his nurse's help, Sharpshooter gradually recovers. However, because he still cannot remember who he is or where he belongs, he takes a new name: John O'Shea. Dr. and Mrs. O'Shea then invite him to live with them and to work at the hospital. Over time, he gains independence and eventually becomes the Night Watch at the Trans-Allegheny Lunatic Asylum.

In 1864, O'Shea's nursemaid and adoptive mother, Dearbhla, goes out in search of O'Shea. She is convinced that the War has confused and harmed him, and decides that she must bring him back. She travels to the Alexandria hospital and asks after him. However, because the man Dearbhla knew no longer looks like himself, has no memory of his past, and has changed his name, Dearbhla cannot find him.

In 1874, Eliza and her daughter ConaLee have survived the War, but continue to struggle for their survival. During the War, a man who calls himself Papa inserts himself into Eliza and ConaLee's lives. He terrorizes Eliza, causing her to retreat further and further into herself. As a result, ConaLee is forced to care for Eliza and her three new babies. Then one day, Papa decides that he is tired of Eliza's vacancy and carts her and ConaLee off to the Trans-Allegheny Lunatic Asylum. He tells ConaLee that this is her new home and that she is to reveal nothing of her life in Virginia with him and Eliza's family to anyone.

Over the course of the following weeks and months, ConaLee and Eliza settle into their new lives at the Asylum. The Matron, Mrs. Bowman, and the resident doctor, Dr. Story, are sympathetic to their alleged plights. ConaLee has crafted a new history for them, per Papa's instructions. Over time, Eliza gradually begins to recover. She grows more energetic each day. Her developing relationship with Dr. Story particularly contributes to her improvement. Meanwhile, ConaLee continues to long for home. She has no interest in staying at the Asylum long term. However, she tries to understand her mother's attachment to the place.

Then one day, Dr. Story has the Night Watch, O'Shea, take ConaLee and Eliza out for a carriage ride. After they return home, Eliza manufactures an audience with O'Shea. She has suddenly remembered that he is in fact her lost lover. O'Shea remembers her, too. They reunite and have sex. Then they go to Dr. Story's office to relay their story. While they are telling him the truth about their past, Papa breaks through the window. As he draws his gun on O'Shea, O'Shea shoves him out the window to his death. O'Shea suffers a fatal gunshot wound. Eliza is devastated. However, she does not leave the Asylum thereafter, even when Dearbhla resurfaces to bring her and ConaLee home.

ConaLee returns to Virginia with Dearbhla and makes a new life for herself. Meanwhile, Eliza makes her own life at the Asylum with Dr. Story. Because Eliza is reestablished, she allows ConaLee to take the money her biological father left in his bank account. ConaLee withdraws the money and begins to dream of buying her own home.