When 2010s Shutter Island was introduced, the psychological horror was an instant success, thanks to Martin Scorsese’s direction and Leonardo DiCaprio’s stellar performance as U.S. Marshal Edward “Teddy” Daniels.  Set in 1954, the chilling tale follows Teddy and his partner, Chuck (Mark Ruffalo), as they investigate the disappearance of a mysterious mother, Rachel Solando, who vanished from an insane asylum on the infamous Shutter Island.  She was committed to the facility after drowning her children.  However, Teddy has ulterior motives for taking the case, and that is to locate an evil arsonist, Andrew, believed to be on the island, who murdered his wife, Dolores, in a fire. 

From there, the many twists and turns are mind-bending, with Teddy having difficulty deciphering what’s real and fake.  After the horrific truth of Teddy’s mission unfolds, a chilling ending will leave viewers on edge, wondering if there is a deeper meaning.  We must warn you that several spoilers lie ahead. 

What Happens on Teddy’s Quest for Answers?

When Teddy and Chuck begin their investigation, they meet Dr. John Cawley and Dr. Naehring, who brief them on the missing woman.  Teddy and Chuck find it strange that Rachel’s lead doctor, Lester Sheehan, has conveniently taken a trip during her disappearance. In the midst of this investigation, Teddy continues to have flashbacks about his deceased wife and experiences relenting migraines.  Though Rachel is the focus, Teddy is still on the hunt for Andrew. 

After having lucid visions of Dolores, who claims Rachel is alive and on the island, as well as Andrew, Rachel suddenly resurfaces.  The woman believes she is Teddy’s dead wife.  As the probe unravels, Teddy continues interviewing staff and patients, including George Noyce. Living in Ward C, George warns Teddy that he shouldn’t trust Chuck or any others on the island, claiming they are each deceiving him.  Even more troubling, George informs Teddy that patients are frequently taken to the nearby lighthouse and lobotomized.

This leads Teddy to forge a plan to reach the lighthouse.  Chuck joins, though after splitting up, Teddy locates a woman living in a cave, claiming to be the honest Rachel. Rachel is a psychologist who claims she was forcibly committed by the facility doctors after discovering the details about what they were doing to patients.  Much like George, the hiding woman issues a severe warning to Teddy, telling him about how the doctors may use his trauma from the army and his wife’s death to have him declared insane as well. 

How does Shutter Island End?

After Teddy returns to the clinic, he encounters Dr. Cawley, who delivers a shocking revelation.  Cawley informs Teddy that Chuck does not exist.  Furthermore, he tells the officer that he arrived at the island completely alone and without the partner he is looking for.  Teddy then begins to believe both the hiding woman and George, who warned him about the staff. He believes they forced Chuck to the lighthouse, but before he can head back to find him, Dr. Naehring tries to sedate Teddy, though he fights back. He finally makes it back to the lighthouse to rescue Chuck but finds Cawley, who informs Teddy that not only is his partner a figment of his imagination, but so is Rachel. Likewise, he insists the terrified Teddy has not been drugged but has instead been on a neuroleptic medication to treat psychiatric disorders. It is at this point that viewers realize this entire mission to find Andrew and Rachel is all one big experiment being conducted on Teddy, who is actually Andrew, the patient he has been desperately seeking.

The stunned man also learns that Dr. Lester Sheehan is actually portraying Chuck, and a nurse is acting as Rachel. The entire scheme is found to be a last-ditch effort by Dr. Cawley and Dr. Sheehan to cure Andrew, who is facing lobotomization.  After accepting the truth, Andrew decides to continue living as Teddy and accepts the lobotomy after realizing that he is actually Dolores’s killer. In his final dialogue with Dr. ​Sheehan, who’d been with him along the experiment, Teddy/Andrew delivers the famous line, “Which would be worse – to live as a monster or to die as a good man?” before going peacefully to receive his operation. 

Shutter Island’s ending is up for debate, leaving some to ponder whether the nurse in the cave was right about Shutter Island staff gaslighting Teddy into believing he was going crazy in order to commit him. However, that seems to be the fun of this twisted horrific fantasy. How would you explain Shutter Island’s ending?