This was a high-risk gamble for the writers. The "will-they-won't-they" tension was the emotional engine of the show. By removing the Duke, Season 4 forces a brutal question: Is Eliza Scarlet a detective because of the Duke, or in spite of him? The season opener wastes no time establishing the new status quo. We find Eliza drowning. Not literally, but financially and emotionally. Without the Duke’s unofficial protection, her male clients are evaporating. The police force, led by a new antagonist, Detective Inspector Fitzroy (played by a menacing Cal MacAninch), views her as a nuisance.
To survive, Eliza takes a case involving a missing aristocrat’s daughter. This case forces her to team up with the one man she swore she never would: Alexander Blake (Tom Durant-Pritchard), a charismatic, roguish ex-convict turned informant. If the Duke is order, Alexander Blake is chaos. Introduced as a morally grey fixer with a silk scarf and a silver tongue, Blake is the most dangerous addition to Season 4. He isn't interested in rules; he is interested in results. Miss Scarlet and the Duke - Season 4
The chemistry between Phillips and Durant-Pritchard is electric but entirely different from her dynamic with Martin. Where the Duke represented safety and frustration, Blake represents temptation and danger. He challenges Eliza’s rigid morality, asking her, "If you catch the killer but ruin an innocent man’s life to do it, are you still a good detective?" This was a high-risk gamble for the writers
In a gut-wrenching scene via correspondence, Eliza writes to the Duke in New York, confessing her struggles. He writes back—solicitous but distant—proving that the Atlantic Ocean is wider than just geography. The episode masterfully uses silence; the absence of the Duke’s booming voice in her office is a character in itself. The season opener wastes no time establishing the
For those willing to let go of the past, Season 4 offers the sharpest writing, the highest stakes, and the most authentic portrayal of a single, working woman in the 19th century since Victoria . Stream it on PBS Masterpiece or Amazon Prime Video. Just bring tissues—not for the mystery, but for the goodbye.