Government official Donnelly brings Ben to the Abbey and forces him to treat Anna, comatose after allegedly murdering two friends.

Ben meets his ex-wife Clara at the Abbey, and she warns him that Anna is a murderer and not a patient to be saved.

Ben plays the song Yesterday for Anna and observes her eyes flicker and her hand move for the first time.

Emily tells Ben that nine-year-old Anna stabbed and killed the family dog Buttons during a sleepwalking episode.

Ben mentions Sally Turner to Bloom, who becomes visibly distressed and abruptly ends their conversation.

Bloom calls Ben in terror from her home and is stabbed to death before he can reach her.

Ben retrieves a hidden blue folder from Bloom's study, following her dying instruction to keep it safe.

Ben reads Bloom's confidential case notes about Patient X, Sally Turner's child, who was treated at Broadmoor Hospital.

Ben begins full sensory stimulation therapy on Anna, using flowers, feathers, music, and one-sided conversations.

Anna opens her eyes and stares directly at Ben, fully awakening from her four-year coma.

Ben tells Donnelly that Anna suffers from post-traumatic amnesia and is not yet ready to stand trial.

Emily is called to the Abbey and tearfully reunites with her daughter Anna for the first time since the murders.

Police arrest Ben and Harriet as suspects, alleging they conspired to drug Anna and frame her for murder.

Harriet dies by suicide in her jail cell, leaving a confessional blog that clears Ben's name and frees Anna from trial.

Clara's final confession reveals she is Patient X, Sally Turner's daughter, who orchestrated everything to avenge her mother's death.

Government official Donnelly forces forensic psychologist Ben Prince to awaken Anna Ogilvy, comatose for four years after allegedly murdering two friends at a wilderness retreat. Ben begins working with Anna using sensory stimulation therapy, interviewing her mother Emily to learn of Anna's long history of violent sleepwalking episodes. When Ben's mentor Bloom is murdered, he retrieves her secret files on Patient X, a mysterious figure tied to a decades-old crime involving a woman named Sally Turner. Ben successfully awakens Anna, but his protection of her from trial backfires when both he and Anna's nurse Harriet are arrested as suspected conspirators. Harriet's confessional suicide note frees Ben and Anna, but the full truth remains buried for years until Ben is killed by Anna in the Cayman Islands. Clara's final confession reveals she was Patient X all along, the true architect of every crime.

The core events driving Anna O's case from coma to deadly conclusion.

Ben is on a dinner date in the Cayman Islands and his companion recognizes him as the psychologist who awakened Anna O.

Ben receives anonymous threatening emails suggesting strangers are watching him and know about Anna's secret location at the clinic.

Lola is revealed as @Suspect8, a true-crime blogger who attended the Farm on the murder night and secretly kept Anna's notebook.

Ben meets Donnelly at a cafe and explains his theory that restoring hope is the key to curing resignation syndrome.

Donnelly agrees off the record to grant Ben access to Anna's confidential files and permission to interview her family.

Emily tells Ben that teenage Anna was caught sleepwalking on video while stealing from her boarding school and was quietly expelled.

Emily tells Ben that Anna attacked her during a sleepwalking episode on a family trip to Greece after college graduation.

Bloom checks her Broadmoor files and realizes Anna's murders occurred on the exact twentieth anniversary of Sally Turner's crime.

Ben and Harriet travel to the Farm and physically reenact the night of the murders to test their theory about Anna's culpability.

At Bloom's funeral, Ben tells Clara he doubts Anna could have walked back to her cabin alone after the murders.

Anna tells Ben about her recurring dream of running through a forest with a knife while the devil breathes through her.

Donnelly privately informs Clara that Anna's description of the devil breathing through her matches the effects of the drug scopolamine.

Ben moves to teach at Grand Cayman University after relentless press harassment forces his family to push him out of London.

Ben is shocked to discover his new patient Elizabeth Cartwright is actually Anna Ogilvy, who has tracked him to the island.

Clara quits the police force and settles into a quiet life with Kitty, confident there are no more threats remaining.

Beneath the headline events of Anna's case runs a web of secondary players and investigative breakthroughs that slowly build the full picture. A true-crime blogger named Lola lurks in the background, manipulating the investigation from her position as a former Farm attendee who secretly holds Anna's stolen notebook. Ben works to understand Anna through confidential files and family interviews, uncovering key sleepwalking incidents that show her escalating danger over the years. Critical revelations — including Bloom's discovery of the murders' anniversary and Donnelly's scopolamine insight — bring investigators tantalizingly close to the truth without exposing Clara. After being disgraced and exiled to the Caribbean, Ben is blindsided when Anna arrives at his island clinic under a false name. Clara closes out the story by quietly stepping back into ordinary life, confident she has escaped any suspicion.

The investigators, obsessives, and hidden clues surrounding Anna's mystery.

Bloom shows Ben a document revealing Anna's brain scans recently changed, indicating she nearly woke up on her own.

A reporter named Isabelle emails Bloom asking if Anna is at the Abbey, later revealed to be Lola impersonating a journalist.

Harriet mentions to Ben that her lover is divorced and has a child, an unwitting hint at her secret tie to Clara.

X breaks into Bloom's home, having already bugged her phones, and decides Bloom must be killed before she makes the full connection.

Bloom's early case notes reveal Patient X is Sally Turner's child — intelligent, vengeful, and privately harboring violent thoughts.

Bloom's final therapy session with Patient X ends with X refusing to confirm whether Sally was truly sleepwalking during the murders.

@PatientX replies to Anna's Twitter inquiry about Sally Turner, offering to be her inside source on the case.

Anna uses Emily's political influence to enter Broadmoor Hospital and discovers Bloom's confidential files on the MEDEA method.

Douglas and Indira confront Anna and reveal they have cut her entirely out of the Elementary magazine sale.

Anna discovers her father Richard and Indira kissing during the paintball game at the Farm, confirming their long-running affair.

Lola drugs Anna with scopolamine in her cabin while a second unidentified woman steps out of the shadows and takes control.

Anna accuses Ben of being Patient X and claims he plotted a decades-long revenge scheme targeting Emily for approving the MEDEA therapy.

Ben feels the scopolamine taking effect as Anna watches him lose control of his body and denies her accusations until his last breath.

Clara reveals she was the one who killed her stepbrothers to protect Sally, having successfully framed Sally for the crime.

Clara reveals she planted the idea of suspecting Ben in Anna's mind during their book interviews, engineering his death as a final cover.

Beneath the surface of Anna's case lie a series of pivotal discoveries and decisions that gradually expose the conspiracy Clara and Harriet built over decades. Early clues — Harriet's offhand mention of a divorced lover, the mysterious X deciding to silence Bloom — hint at a hidden network long before readers can decode them. Anna's own pre-Farm investigation uncovered a web of betrayal involving her father's affair, her magazine's hostile takeover, and an anonymous source named Patient X who guided her toward Broadmoor and the buried MEDEA files. On the fatal night, Lola's role as drug-carrier and the presence of a shadowy second woman are revealed in Anna's fragmented account. The climax brings Anna's lethal but mistaken accusation against Ben, followed by Clara's private confession that she killed her stepbrothers, engineered Sally's tragedy, and deliberately steered Anna toward the wrong man. Every turning point in this pool reveals a layer of deception that only fully resolves once Clara's identity as Patient X is finally exposed.

The hidden revelations and turning points that expose the real truth behind Anna O.