Rachel McAdams looked beautiful at the "Sherlock Holmes: A Game of Shadows" Los Angeles premiere last night. She bared her back in a floor-length silver dress with a train.

The actress swept her hair back and wore minimal jewelry - diamond studs and a diamond pinky ring.

In the film, Sherlock Holmes (Robert Downey Jr.) matches wits with the nefarious Professor Moriarty (Jared Harris) after uncovering a diabolical plot to destabilize the entire Western world. The film also features Jude Law, Eddie Marsan and Noomi Rapace (2009's "The Girl With the Dragon Tattoo.")