Laurence Olivier once observed that he "learned more about acting from watching [Spencer] Tracy than in any other way." Undertaking the dual title role in Robert Louis Stevenson's Victorian science-fiction thriller, Tracy fulfilled that compliment by abandoning his characteristic down-to-earth image for the most terrifying portrayal of his career. Also cast "against type" are "Sweater Sweetheart" Lana Turner as Jekyll's fiancee and Ingrid Bergman, who plays Hyde's victimized Cockney mistress. Tracy and director Victor Fleming (Gone with the Wind) decided to break with convention by interpreting Hyde from a Freudian perspective instead of portraying him as the usual physically grotesque monster, and he emerges as a menacing distortion of the sexually frustrated Jekyll. To Tracy fans, this amazing piece of virtuosity will come as an unforgettable revelation.