Shutter Island of Dennis Lehane, a contemporary American author, focuses on the complex inner life of the protagonist, Teddy Daniels, who is indeed a patient of Aschecliffe Hospital. Although the novel presents a detective fiction contingent upon the investigation of a patient’s disappearance, the protagonist lures the reader’s attention to impetuous and recalcitrant behaviours which reflect his dreams and hallucinations including the murder of his wife and children. Due to these horrendous memories, he refuses to accept the reality and creates his fictional reality that he, doctors, and officers of the hospital play different roles every time. However, realities he prefers to keep in his unconscious appear through his perpetual dreams and hallucinations. Carl Jung, one of the leading figures of analytical psychology, concatenates dreams and personal unconscious that their balance is crucial for psychological health. The protagonist is not able to demarcate hallucinations of dead wife and children from so-called detective identity. Therefore, this article aims to peruse the relationship between dreams and unconscious of Teddy Daniels regarding Jung’s analytical psychology perspective, in particular dreams, hallucinations, personal unconscious, and shadow.