Shutter

U.S. Marshals Edward Daniels and Chuck Aule are summoned to Shutter Island, a federal mental hospital. Their mission is to investigate the escape of a patient named Rachel, who fled the facility just one day prior.

Upon arrival, Teddy and Chuck meet Dr. Cawley, the lead psychiatrist, who reveals differing opinions among the staff about treating patients. Some believe in surgical techniques like lobotomies, while others advocate for treatment with psychotropic drugs.

Dr. Cawley explains Rachel’s troubling history as a mother who murdered her three children. She has been living in a delusion, believing her kids are still alive and that the staff are their neighbors.

While searching Rachel's room, Teddy finds a note that asks, 'Where is number 67?'. This clue piques his curiosity and drives him deeper into the mystery surrounding Rachel’s escape.

Throughout the investigation, Teddy experiences vivid flashbacks from his time as a soldier during WWII. These memories haunt him, particularly his experience witnessing the horrors at the Concentration Camp Dachau.

Teddy meets Dr. Naehring, a German psychiatrist who refuses to provide personnel records. Their interactions heighten Teddy's distrust, further complicating his search for the truth about Rachel.

Teddy comes across George Noyce, a patient who claims to know vital information about the facility. Noyce advises Teddy to abandon his pursuit of Laeddis, suspecting a conspiracy at play.

The next day, a power outage causes the cell doors in the facility to open. Teddy and Chuck seize the opportunity to venture into Building C, where the dangerous patients are housed.

Teddy learns about a lobotomy scheduled for Laeddis in the lighthouse. Despite Chuck's warnings, Teddy decides to confront the truth and make his way to the lighthouse.

In a cave, Teddy encounters a woman who claims to be Rachel. She warns him of the hospital's methods and urges him to resist their manipulation, suggesting that he may be labeled insane for his inquiries.

At the lighthouse, Teddy confronts Dr. Cawley, who reveals startling truths about Teddy's identity and mental state. It is exposed that Teddy is actually Andrew Laeddis, who has created a delusional world to escape his trauma.

Dr. Cawley explains that the staff have been conducting a role-playing experiment to help Teddy confront his past. The intention is for him to accept the truth behind his delusions and recognize his real identity.

Realization dawns on Teddy as the doctors draw him closer to his painful memories. He struggles with his past actions, the loss of his wife, and the tragic fate of his children, eliciting a deep emotional turmoil.

In the end, Teddy shows signs of regression, indicating that he may choose to remain in his alternate reality rather than confront the painful truth. He implies he might voluntarily submit to lobotomy, preferring to escape his haunting memories.