Christine (played by Rachael McAdams) is freaky in the sack. She role plays with a mask of what looks like her own face. This creates the sense that she is constantly making love to herself. The mask might also represent her mythical twin sister … who may or may not exist. She’s in love with herself, she’s in love with her twin. Her twin sister Clarissa, was accidentally killed when Christine was younger, she tells Isabelle (Noomi Repace), and Clarissa feels responsible.