"It's strange calling yourself." Betty Elms with Rita about to call "Diane."
"You want me to make this easy for you? No fucking way! It's not gonna be. It's not easy for me!" Diane throwing Camilla Rhodes out of her apartment.
Diane Selwyn (aka Betty Elms) is the main character and antagonist in David Lynch's 2001 psychological thriller "Mulholland Drive." She is introduced to the story as Betty Elms, and remains so for the first 3/4 (or so) of the film. However, in the last fourth of the film, her real name is revealed to be Diane Selwyn. She is played both times by Naomi Watts.
As Betty, she is shown to be sweet, innocent and accomodating. She takes in an amnesiac woman named Rita (Laura Elana Harring,) after her car crashes. Betty goes to Hollywood (where she meets Rita) to become an actress. She stays in her Aunt Ruth's apartment, while her Aunt is away. She goes to an audition held by the director Adam Kesher (Justin Theroux.) However, she becomes intimidated by "Camilla Rhodes," (Melissa George,) who lipsyncs a song called "Every little star." Betty runs off, and returns to help Rita find the apartment of a friend named "Diane Selwyn." Upon arriving, a neighbor informs them that she switched apartments with Diane and that she hasn't seen Diane for a while. They break in, only to find Diane dead. Arriving home, Rita blames herself, and puts on a blonde wig, simliar to Betty's hair style to disguise herself. With this on, Betty and Rita have a lesbian excounter (possibly a symbol for Diane's true narcisism.) The two go to a myserious night club and listen to a lipsynced Spanish version of Roy Orbison's "Crying." (The lypsincing possibly hints that Diane is incapable of true affection. They return home, open a myserious box and disapear. A mysterious entity called hte cowboy arrives in Diane's apartment and tells her to wake up.
As Diane, she is shown to be a drug addict, who was infatuated with her room mate Camilla Rhodes (Harring not George now,) until Camilla had an encounter with both a wairess (George) and Adam Kesher. As a result, Diane's acting career was lost to Camilla who managed to secure her small film roles as an act of charity. When she arrives at the drug addled Diane's apartment, Diane makes inappropriate advances. She follows Camilla to the set of her new film and is there jealous of both Camilla and Adam.
In a sequence which mimics the opening with Rita, Diane is invited to dinner at Adam's house. There she meets Adam's mother Coco (Ann Miller,) who she once imagined as her land lord. Adam and Camilla are now a couple and it is implied that they are secretly engaged. The next day, Diane orders a hit on Camilla. And at home, it is revealed that Diane changed apartments to get away from the police. The crone (shown in an earlier sequence) causes Diane to realize what she's done as she learns that Camilla is dead, and out of guilt, Diane kills herself. The final shot shows the woman from the nightclub, reminding Diane that even in her dream, she never loved Camilla (Rita) and that even in death, Camilla is superior to her.