Theo Faber, a respected psychotherapist, describes a sensational murder from six years earlier. Late one August night, Alicia Berenson, a renowned painter, shot her husband Gabriel five times in the face. After the murder, Alicia was tried, found guilty, and institutionalized at the Grove, a psychiatric ward. Through it all, she never said a word—earning herself the nickname “the silent patient.” Her only comment is a self-portrait entitled Alcestis.
After a period of intense media attention, most people lose interest in the case. But Theo is so drawn to Alicia that he leaves his job to work at the Grove, taking her on as a patient. At the Grove, Theo connects with Lazarus Diomedes, the head of psychiatry, with nurse Yuri, and with fellow therapist Indira. But he spars with Christian, an old colleague who prefers to prescribe medication rather than talk through issues.
As Theo begins to treat Alicia, he reflects on his own troubled childhood. Theo had an abusive father and an ineffectual mother; his only happy memory from childhood is of playing in the snow by himself. Though he was able to get out of his home and go to college, Theo was so haunted by his father’s mistreatment that he tried to kill himself. Fortunately, after a failed suicide attempt, Theo found solace in his therapist Ruth, whose warmth and wisdom inspired him to become a therapist himself.
In the present, Theo digs into Alicia’s file, learning about her relationships in and outside of the Grove. He discovers she was in a violent altercation with a woman named Elif, one of the ward’s most fearsome patients. He also introduces himself to Alicia’s former gallerist Jean-Felix Martin. Though Theo realizes he is obsessing over Alicia, he feels that he is powerless to stop himself from going deeper: “his fate was already decided—like in a Greek tragedy.”
Meanwhile, in a series of diary entries from the summer of the murder, Alicia describes her relationship with Gabriel. She loves him so much that it scares her—she even wants to paint him as Jesus Christ. Alicia is also haunted by memories of her mother’s suicide.
Theo reflects on his relationship with his wife Kathy, a lovely, energetic actress. One night, however, Kathy accidentally leaves her laptop open—and Theo discovers she has been having an affair. Theo visits his old therapist Ruth, who encourages him to leave Kathy, but Theo ignores her advice. Instead, he focuses more on work, promising Alicia that he wants to help her “see clearly.” Suddenly, in a fit of rage, she attacks him.
Despite the attack, Theo only tries to get closer to Alicia. To learn more about her, he goes to meet Gabriel’s brother Max Berenson and his receptionist-turned-wife, Tanya. Whereas Gabriel was handsome and charismatic, Max is unattractive and frightening. Max tells Theo that Alicia has a long history of mental illness: after her father died, she had tried to kill herself. When Theo calls Max to follow up, Max complains to Diomedes.
The novel returns to Alicia’s diary entries. She reveals that Gabriel keeps a gun in their house, a topic of much conflict between the couple. Even more shockingly, Alicia reveals that Max is secretly in love with her—on multiple occasions, he has forcibly assaulted her, kissing and groping her while Gabriel is in the next room.
Theo then travels to Alicia’s childhood home, where he meets her adoring younger cousin Paul and her angry, morbidly obese Aunt Lydia. Lydia has always hated Alicia, and Theo finds himself overcome with pity and disgust for the whole family.
Theo visits Jean-Felix, Alicia’s gallerist, and studies several of Alicia’s paintings. Jean-Felix insists that Alicia’s silence is her message, and he urges Theo to read a copy of Euripides’s Alcestis, the play on which Alicia’s self-portrait is based. In the play, Alcestis’s husband Admetus asks his wife to sacrifice her life for his own. Though Alcestis is eventually revived and brought back to earth, she never speaks again.
Through diary entries, Alicia reveals that, in the weeks leading up to the murder, Paul had asked to borrow money—he had a serious gambling problem, and he was in debt. And just a few days before Gabriel’s death, Alicia had severed her professional relationship with Jean-Felix, much to his despair.
In the present, Jean-Felix suggests that Theo should allow Alicia to paint as a way to express her feelings; Theo thinks this is a wonderful idea. Back at home, Theo follows Kathy, but he is unable to catch her in the act of betrayal. His only moment of relief comes when Alicia, still refusing to speak, gives Theo her diary to read.
In the diary, Alicia explains that she has started to notice a man following her and watching the house. She tells Gabriel, but he dismisses her, claiming either that the man is Jean-Felix or that she is hallucinating things. Alicia also tells her narcissistic neighbor, Barbie Hellman. Gabriel, fearing that Alicia is going insane, forces her to see a therapist friend of his: Dr. West. Dr. West prescribes Alicia more pills, but she secretly refuses to take them.
Theo connects the dots—Dr. West is Christian West, his colleague. Theo confronts Christian with his knowledge, assuring Alicia that he is trying to protect her. Alicia finishes her picture, which depicts the Grove on fire. In the painting, Theo and Alicia stand in the doorway, and it is unclear whether Theo is rescuing Alicia or throwing her into the flames.
After work, Theo follows Kathy to a park, and this time, he sees her with a man. He listens to them have sex in the woods, and he resolves to kill the man. But after following the man home, Theo decides that he is not a murderer—instead, he will have to do something “cleverer.” As he continues to spy, he notices that Kathy’s lover has an adoring wife of his own.
Theo returns to Alicia’s childhood home, where he learns a disturbing story: after her mother died, Alicia’s father Vernon told her he wished Alicia had been killed instead. Theo feels that he has unlocked the key to Alicia’s psyche—and sure enough, she soon starts speaking, telling him her life story. However, when she describes the night of the murder, Theo is convinced she is lying. The next morning, Alicia is hospitalized, having been found comatose. Diomedes thinks she has overdosed, but Theo suspects murder. The police arrive, and Theo reveals that he thinks Christian is the culprit.
Theo returns to Kathy’s lover’s house, and he sees the man’s wife again. Theo then breaks into the house, and the wife turns around, revealing herself to be Alicia Berenson. Readers discover that Theo has willfully manipulated the timelines of the novel: Kathy’s affair with Gabriel happened years ago, before the murder, and Theo has been the man watching Alicia all along.
In a final diary entry, written just before sinking into a coma, Alicia tells the entire truth of what happened with Theo. He had entered the house, taken Gabriel’s gun, and told Gabriel to choose whether to die or whether to sacrifice Alicia. Gabriel chose his own life over Alicia’s—and though Theo left before enacting any violence, Alicia, horrified at the betrayal, then shot her husband five times.
In the present day, Theo and Kathy have moved to Surrey, outside of London; Kathy is depressed, and the two almost never speak to each other anymore. Chief Inspector Allen, the man in charge of Alicia’s case, arrives at Theo’s house. The inspector reveals that Alicia has written a final diary entry, one which almost certainly incriminates Theo. In the closing scene, Theo tries to catch snowflakes on his tongue as Inspector Allen reads the entry aloud.