Despite receiving five Golden Globe Nominations (MP) and three BAFTA notices, Mia Farrow has never been nominated at the Oscars. Puzzlingly, none of those nominated performances include her brilliant turn in Death on the Nile, where she plays the drunken, jealous ex of a British tourist. Her presence in Rosemary's Baby, however, is probably the closest she came to a date with the Golden Guy crew, given that the film managed a Screenplay nomination, and a Supporting win for Ruth Gordon, as well as the fact she's in nearly every scene.
Farrow's role is, quite obviously, not a stock one, as the initially enthusiastic and eager-to-settle Rosemary eventually becomes a wailing beacon of paranoia. As with most horror films, the establishment of equilibrium wants us to see Rosemary as a familiar, fawn-like heroine, walking blindly into a hunter's trap. It works: Farrow, as ever a warm and easy presence on-screen, gives us the foothold of honesty that we need, but she also lets us see the pretense in her attempts at home-making, the inherent motivation of the woman to dismiss or distract from the insecurities of her relationship with Guy (Cassavetes). As a character, Farrow makes Rosemary, timid in demeanor but clear in focus, feel above and beyond her malleable surroundings; immersed, impelled, thoroughly self-alienating, and an awfully easy target.
In many ways, Rosemary's fate is an inevitable one. Lord knows, there's defiance and fight in this woman, but the apparent victory of her conception blinds her from realising (at least for a while) that she does not have everything her own way. She even endures pain for months on end, believing that it's down to purely natural behaviour. But as the penny starts to drop, and Rosemary is forced to exercise her suppressed challenge and independence, is where Farrow unquestionably excels.
The success of Polanski's film most lies in its nonchalance; the denial, the unspoken. Its mellow tone simmers and starts, but rarely goes into overload, and keeps the overt drama to a bare minimum. The idea of satanism and witchcraft is something Rosemary would surely have balked at at one time or another, but believably forms the underlying basis of her newfound drive and purpose, as much of a way to free herself of the restrictions of pregnancy than to find hidden truths. Farrow masters the confluence of comedy, perplexion, investigation, and fear, whacking up the intensity but sticking with the character's narrow perceptions, and embedding her descent into fully-fledged realisation with the scorn of an exploited woman. One gets the impression that she feels as bloodthirsty as she does wronged, and the final scene handily leaves you exactly that to ponder.