A psychologist working in London during 1906 explores Freudian ideas while conducting experiments involving drug injections, a process that ultimately has negative consequences for him. “I, Monster” (1971) alters the names of the central character—played by Christopher Lee—to maintain the impact of the story’s familiar plot development in “The Strange Case of Dr. Jekyll and Mr. Hyde.” This decision was made because numerous film adaptations had already been produced. Hammer Films released a version, "The Two Faces of Dr. Jekyll," eleven years prior and were also creating another variation concurrently, titled “Dr. Jekyll and Sister Hyde.” The production team even attempted to conceal the connection to Robert Louis Stevenson’s story in the opening credits. It's easy to understand why this film isn’t widely known, as it doesn’t reach the level of enjoyment found in "Two Faces." It adopts a subdued style, emphasizing the psychological aspects of the original novella and incorporating Freudian concepts into Stevenson's narrative, set twenty years after the story's initial publication. The editing occasionally feels problematic; certain details are left unclear instead of being explicitly presented, such as Marlowe’s administration of his experimental drug to Diane. This moment isn't depicted directly, requiring viewers to infer what happened. It seems likely that BBC guidelines at the time discouraged showing injections on screen. Despite these shortcomings, Christopher Lee delivers one of his most nuanced performances, making the film worthwhile for that reason alone. The psychological theories presented are also engaging, and there are some amusing moments scattered throughout. However, the notion that Marlowe’s colleagues wouldn't recognize him as Blake stretches credibility; the visual differences aren't substantial enough to support this plot point. The movie has a running time of 1 hour and 20 minutes and was filmed at Shepperton Studios, situated southwest of London. GRADE: B-

Source on TMDB