Shutter Island - Easter Eggs & Hidden Details

The music used in the film's opening sequence is a direct reference to Stanley Kubrick's "The Shining." The piece by composer György Ligeti was also used in Kubrick's film to create a sense of dread and tension. This musical choice serves as an homage and immediately sets a similar tone of psychological horror and isolation.

Throughout the first act, there are numerous subtle clues that hint at the final twist. For instance, when the marshals arrive, the guards are on high alert and handle their weapons nervously around Teddy, not Chuck. Chuck also struggles to unholster his gun, suggesting he's unfamiliar with firearms. Teddy's toy gun is also a hint. These details, easily missed on a first viewing, foreshadow that Teddy is a patient and Chuck is not a real marshal.

In a scene where Teddy interviews a patient, Mrs. Kearns, she asks for a glass of water. As she drinks it, there is a brief cutaway where the glass is missing from her hands, then it reappears. This is not a continuity error but a deliberate visual cue representing the unreliable nature of Teddy's perception and the manufactured reality of the situation. It hints that the events are not as they seem and are part of his delusion.