Rowena Price (Halle Berry) is the main protagonist and hidden main villainess of the 2007 film Perfect Stranger. She was a New York journalist and a childhood friend of Grace Clayton, but cut her out of her life years prior to the film. She re-encountered her on the subway, where Grace offered her a story about Harrison Hill, the head of a successful advertising agency and Grace's lover (as well as the father of her unborn child).
When Grace was later found murdered, having been poisoned with belladonna before being drowned, Rowena went undercover to prove that Harrison had killed her to prevent his infidelity from being exposed, with her friend and researcher Miles Haley helping her in her plot. Unbeknownst to her, however, Miles was posing as Hill online as part of his lustful affection for her, despite her being in a relationship with her boyfriend Cameron.
Despite Miles' interference, Rowena's plan to seduce Hill began to succeed until Harrison saw a text from Miles on Rowena's phone after taking her out to dinner. When confronted by Harrison in her car, Rowena confessed to being a spy, resulting in Harrison firing Rowena. Later on, though, Miles posed as I.T. to gain access to Hill's computer, during which time Rowena went to his apartment saw evidence to Miles' obsession for Rowena and his past sexual relationship with Grace. Rowena confronted Miles about his actions when he returned home, during which she accused him of murdering Grace and framing Hill.
But in the film's climax, after Hill was arrested and convicted for Grace's murder, it was revealed that it was Rowena who had killed Grace and used the investigation into Hill to cover for herself, with her villainous reveal occurring when she revealed she was hiding a bottle of belladonna in her medicine cabinet. Her backstory revealed that her father was attempting to molest her as a child, with her mother killing him when she caught him, later forcing Rowena to help her bury the body. Grace witnessed the act, and began blackmailing Rowena with her secret in adulthood. To stop the blackmail, Rowena met with Grace and gave her a drink laced with belladonna, taking her hairs and blood and planting it in Hill's car to frame him.
Miles confronted Rowena about her villainous plot, having previously figured out her secret, and subtly threatened to expose her secret if she didn't sleep with him. At that, however, the evil Rowena stabbed and killed Miles with a knife before trashing her apartment and planting the belladonna bottle in Miles' pocket, later calling the police and tearfully claiming that Miles was Grace's killer and had attacked her, even using Miles' fingers to scratch her neck. Rowena then laid down next to Miles' corpse, unaware that her next door neighbor had witnessed everything.
- Halle Berry also appeared in 2001's Swordfish as the evil Ginger Knowles.