Mary Duncan, an American actress born in 1895, captivated audiences during the silent film era and into the early sound age. Best remembered for her role in the lost Murnau film *4 Devils* (1928), Duncan’s work has become a holy grail for collectors and film historians alike. The film, notable for its avant-garde storytelling and stunning visuals, is highly sought after due to its rarity and the intrigue surrounding its lost status. Duncan's early stage career, including her impactful performance in the controversial play *The Shanghai Gesture* (1926), showcased her talent and positioned her as a memorable figure in theatrical and cinematic history. Though she retired from acting after marrying polo player Stephen "Laddie" Sanford in 1933, her legacy endures through her performances and the elusive nature of *4 Devils*. Collectors value her films not only for their artistic merit but also for their historical significance, making her a fascinating subject within the realm of physical media. As the last known possessor of a copy of *4 Devils*, Duncan's connection to this piece of cinematic history adds a layer of allure for those passionate about preserving the art of film.