The mysterious, beautiful woman has always been a cinematic fixture. Rachel Weisz takes on the role in Complete Unknown, and while she is a compelling performer, this Hitchcock-inspired thriller doesn't actually have too many thrills. We first see her character, Alice, in a number of different guises: as a hippie, a doctor and, most intriguingly, a magician's assistant. She later shows up at a dinner party as the date of one of the coworkers of Michael Shannon's Tom. Tom just knows that he knows her, somehow, but Alice denies any connection. The plot then thickens as she reveals her multifaceted identities to him -- but never quite enough. "I could be anyone I wanted, and I could do it again and again," she says, in one of many bits of intriguing but overly expository dialogue.
Complete Unknown would benefit from more exploration of Alice's past personas: We see promising bits and pieces that allow Weisz to channel a few different versions of femininity. The interplay between the two is prickly: Alice goads Tom into pretending he is a doctor as the two help an injured woman (Kathy Bates). Tom never goes quite as far as Alice -- she represents a strange life that seems in complete opposition to his unfulfilling job. At one point Alice offers this bit of philosophizing: "When everyone thinks they know who you are, you're trapped." It's true, and while her enigmatic quality is appealing, the movie she's in, which never truly grabs us with eroticism or fear, might not be unknowable enough. It has potential for weirdness, but stays far too tame.