While Martin Scorsese’s best-regarded work is usually an examination of the human experience, his genre work is equally fulfilling, from the whimsical delights of Hugo (2011) to the B-movie-ness of Cape Fear (1991) to the engagement one feels with The Departed (2006). Shutter Island, his 2010 psychological thriller headlined by Leonardo DiCaprio, is no different, except its ending has a deliberate lack of narratorial clarity.
The disappearance of an inmate at a psychiatric facility on an island necessitates an investigation by US Marshals Edward “Ted” Daniels (DiCaprio) and Chuck Aule (Mark Ruffalo), who make their way across the choppy waters under a grim, grey-blue sky, and soon find themselves cloistered with the facility’s director Dr. Cawley (Ben Kingsley) who, in laying down the laws of the island, appears to be a hurdle rather than a helping hand.
The Marshals conduct interviews and walk the beat around the facility in the hope of happening upon a clue. They find nothing. Amid this, Daniels confesses to Aule that he has an ulterior motive for coming to Shutter Island: to find Andrew Laeddis, an arsonist whose actions led to the death of Daniels’ wife and who was subsequently committed to Shutter Island. The mystery thickens even more when the missing inmate resurfaces, and then Daniels breaks into Ward C, declared out-of-bounds by Cawley. An inmate named George Noyce recognises him and alerts him about experiments being conducted upon inmates in the lighthouse, while also advising caution, and a perpetual distrust of everyone, including Aule.
Daniels and Aule make for the lighthouse, but the latter disappears and Daniels winds up in a cave housing a woman who claims to be the missing inmate who was earlier a member of the medical staff at the facility. She claims to have been committed when she discovered the truth about the experiments. She warns Daniels that Cawley and Dr. Naehring (Max von Sydow) will try to have him committed too, and this possibility crops up immediately upon Daniels’ return to the main facility, when Cawley insists he arrived on Shutter Island by himself.
Convinced that Aule has been abducted and taken to the lighthouse, Daniels makes his way there. When Naehring tries to sedate him en route, Daniels overpowers him. In the lighthouse, Cawley awaits him patiently, and when confronted with Daniels’ theories, tells him that he has been a patient at Shutter Island for the last two years, a consequence of murdering his manic-depressive wife after she had killed their children. Andrew Laeddis, Cawley explains, is his real name, and Edward Daniels an alternate identity he created using the same alphabets as his actual name. Moreover, his partner Aule is one Dr. Sheehan, also on the facility staff.
Cawley then reveals to Daniels/Laeddis the entire plot: that the investigation mounted by him and Aule is an elaborate ruse concocted by the facility doctors in the hope of making the deluded Daniels realise he is actually Laeddis and come to terms with his reality.
Laeddis passes out, and wakes up in a ward, where he accepts his true identity. Cawley warns him that another lapse in his state of being would result in lobotomization.
Laeddis is joined on the facility lawns by Sheehan, and commences their conversation by addressing him as he would Aule, suggesting that he has not been successful in holding on to his identity. Sheehan signals to Cawley that Laeddis has exhausted his last chance, only to be asked a rather lucid question by the condemned man: ‘Which would be worse – to live as a monster or to die as a good man?’ When a rattled Sheehan addresses him as Teddy right after, Laeddis ignores him and walks off for his operation, apparently content with the state of affairs.