Shutter Island ending explained: What really happened to Leonardo DiCaprio’s Teddy?

However, it soon becomes apparent that not all is as it seems, leading to a shocking plot twist in the finale and an intentionally ambiguous ending that is still spawning endless theories, debates and examinations to this day.

While the Shutter Island ending is left open to interpretation in many ways, we've picked it apart below, including that haunting final line. Be warned, though, major spoilers follow.

Shutter Island ending explained

Explaining what exactly happened in Shutter Island is quite the task, but here's a concise explanation of the events leading up to that all-important ending.

The film starts with U.S. Marshal Edward "Teddy" Daniels (DiCaprio) and his partner Chuck Aule (Mark Ruffalo) arriving at the titular island in 1954, where they are to investigate the disappearance of a patient from Ashecliffe Hospital for the criminally insane. The patient in question is Rachel Solando, who was sectioned for drowning her three children, with the only clue to her disappearance a cryptic note found in her room reading: "The law of 4; who is 67?".

Fittingly for a psychological thriller, a dark and gloomy storm rolls in which prevents the two men from returning to the mainland for several days - and the amount of water seems to make Teddy very uncomfortable.

Teddy and Chuck struggle to get information from the uncooperative staff, with lead psychiatrist John Cawley (Ben Kingsley) refusing to hand over records while Solando's doctor Lester Sheehan is away on a sudden vacation. They are also barred from areas of the hospital such as the lighthouse and Ward C, which houses the most dangerous patients.

Teddy soon starts to experience migraine headaches, which trigger visions of traumatic incidents from his past - specifically his involvement in the liberation of Dachau in World War Two, and visions of his wife Dolores Chanal who died in a fire caused by arsonist Andrew Laeddis. During one of these visions, Dolores explains that Solando is still on the island - as is Laeddis, with Teddy later telling Chuck that he took the case in an attempt to locate his wife's killer.

After reports that Solando has apparently returned, Teddy breaks into Ward C where he encounters George Noyce (Jackie Earle Henley), a patient in solitary confinement who claims that patients are being lobotomised in the lighthouse - and that everyone on the island is conspiring against Teddy in an elaborate game.

Teddy interviews Rachel Solando (Emily Mortimer) who seems to think that he is her dead husband.

Reunited with Chuck, Teddy heads towards the lighthouse, only to lose his partner near the cliffs and seemingly spot his body on the rocks. Teddy heads towards Chuck's corpse - revealed to just be an optical illusion - but discovers a cave inhabited by a woman (Patricia Clarkson) who claims to be the real Rachel Solando. She claims that she discovered experiments with psychotropic medicines on the island in an attempt to perfect mind control, and was forcibly committed to the island before she could go to the authorities.

Solando also suggests that the hospital has drugged Teddy, and will soon concoct a story that he went crazy in order to keep him on the island.

Teddy returns to the hospital in search of Chuck - but Dr. Cawley insists that Chuck does not exist and that Teddy arrived on the island alone. A now paranoid Teddy sets fire to Cawley's car and uses the diversion to flee to the lighthouse as his hallucinations worsen.

Shutter Island comes to a heartbreaking conclusion at the lighthouse, where Teddy does not find evidence of experiments - but instead Dr. Cawley waiting for him there.

Cawley denies that he has drugged Teddy, and explains that Teddy is experiencing withdrawal symptoms from the anti-psychotic medication that he has been taking for the last two years.

Cawley explains that Teddy is in fact Andrew Laeddis, the most dangerous patient in Ward C.

Teddy/Andrew was incarcerated on the island after he murdered his manic depressive wife Dolores, who drowned their three children.

Edward Daniels and Rachel Solando are revealed to be anagrams of Andrew Laeddis and Dolores Chanal, and Andrew attacked George Noyce two weeks ago for calling him Laeddis.

Andrew Laeddis took up drinking after the horrors he witnessed at Dachau, which meant he failed to seek mental health for Dolores who burned down their city apartment in a suicide attempt. Instead he moved the family to a lake house, where Dolores' mental issues led to her drowning the three children.

Andrew created the Teddy persona as a result of his guilt for not helping his wife sooner, and the events of the film were all part of a role-play designed by Cawley to help Andrew accept reality. Chuck was in fact a hospital staff member called Dr. Lester Sheehan, and a nurse played the role of Rachel Soldano. The "real" Rachel Soldano was a hallucination caused by withdrawal symptoms from his medication.

Andrew faints and awakens in the hospital surrounded by the hospital staff. He relays the truth they told him when questioned, which satisfies Cawley - but warns Andrew that it is his last chance or he will be lobotomised.

However, sometime later on the hospital grounds Andrew refers to Sheehan as "Chuck", and says that they must leave the island. Sheehan looks at Cawley and shakes his head, and Andrew is taken away to be lobotomised.

However, as he is taken away, Andrew asks Sheehan"Which would be worse: To live as a monster, or to die as a good man?” Sheehan calls Andrew "Teddy" one last time, but gets no response.

Did Andrew get lobotomised voluntarily?

Andrew's last line of dialogue, and his failure to respond to being called Teddy, has led many fans to speculate that Andrew had not actually regressed, and was voluntarily submitting himself to a lobotomy so he did not have to live with his sins and the monster he had become.

Neither Scorsese nor any of the filmmakers have given a conclusive answer. However author Dennis Lehane, who wrote the 2003 novel of the same name on which the film was based, had some opinions, despite the book ending far more conclusively.

"When he asks the question, he does it in such a way that, if he were to say it as a statement... then there's no solution here but to stop the lobotomy,” Lehane told MTV. “Because if he shows any sort of self-awareness, then it's over, they wouldn't want to lobotomize him.

"My feeling was no, he's not so conscious he says 'Oh I'm going to decide to pretend to be Laeddis so they'll finally give me a lobotomy.' That would just be far more suicidal than I think this character is. I think that in one moment, for a half a second sitting there in that island he remembered who he was and then he asks that question and he quickly sort of lets it go. That was my feeling on that line."

Was Teddy/ Andrew sane at the end of Shutter Island?

The beauty of this film is how well it works in two ways - it works as the investigation of a U.S. Marshall, but also makes sense retroactively when it is revealed the whole thing was a ruse.

This means that it could be argued that Andrew had a mental break after seeing his dead children, murdered his wife and then could not accept reality while in the hospital.

Alternatively, it could also be argued that Teddy is mentally sane, never killed his wife, really did meet Rachel Saldano in the cave, and was lobotomized so he would not tell the world.

While the movie never does not quite discount either interpretation with concrete proof, it does tend to lean towards the idea that Andrew really was a patient on the island struggling to accept the death of his family.

Andrew never does find any evidence - even while hallucinating - of experiments taking place in the lighthouse, and a rewatch will result in several clues that hint towards the plot twist...

Shutter Island clues that foreshadow the ending

Throughout the film there are several hints and continuity errors that suggest all is not quite right, and make tragic sense following the big reveal. These include:

• Teddy's aversion to water throughout the film - a subconscious reminder of his drowned children.
• Teddy refuses to light his own cigarette at the start of the film, clearly an association with arson and his wife's first suicide attempt. However as the personalities start to merge Teddy starts lighting his own cigarette, and eventually blows up a car while hallucinating about his wife.
• Chuck struggles to unholster his gun when entering the island, suggesting he is inexperienced with firearms.
• A cardigan briefly worn by the fake Rachel appears later on the "real" Rachel.
• Lines from Teddy's dreams being repeated by other characters show he is struggling to distinguish dreams from reality
• When Teddy grabs Peter Breene, Chuck can be seen signalling the hospital staff.
• When Teddy mentions Dr. Sheehan while interviewing Bridget, Bridget can be seen glancing at Chuck.
• During the patient interviews there are always guards behind Teddy, but not Chuck.

Shutter Island Reddit threads that actually make a lot of sense

With a film as ambiguous and mind-bending as Shutter Island, it was hardly surprising that the people of Reddit had some theories and opinions. However what might be surprising is that some of them made quite a bit of sense - here are some of the best:

Reddit user hankmeisterr made a thread titled "All sci-fi stories come from mentally ill people in Shutter Island" complete with a picture of Pokemon's Ash Ketchum feeding a mouse in a mental ward. Depressing for sure, but it would explain a lot of plot holes...

Fellow redditor IndiaSpeaks shared a clip from the film which shows "Chuck" and a nurse laughing at Teddy behind his back - a clip they believe "will end the theory that Leonardo is detective".

Meanwhile, HauntedPlanter26 took a different approach, not questioning Teddy's sanity but instead querying whether escaped patient Rachel Soldano was a real person or not - or whether she was an actual ghost. The argument here is that Rachel is an anagram of Dolores, but "yet the whole time [Rachel] interacts with Teddy she is raw and sincere, NOT AT ALL like the creepy tantalising personality of his wife Dolores". As a ghost who was delusional in real life who believes she was wrongly imprisoned, she believes Teddy when he says he is a detective and prompts him to keep investigating. Interesting stuff...

Abdullah_Awadallah was still convinced that Teddy is sane, arguing in a post that all the evidence of him being insane only happens AFTER he takes the medicine from the warden - and therefore he actually was drugged and brainwashed. The Reddit user also points to a cup that disappears from a patient's hand shortly afterwards - suggesting that we shouldn't believe everything we see or hear from that point forward...

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