Casting Change: Sarah is Joined By Nadine

"Nadine Ferguson? What the hell are _you_ doing here?" Sarah asked, upon seeing the new arrival. As always, the teenage girl was dressed like a total prude with no fashion sense, her hair in a bun, and wearing a cross necklace. "No, she's not doing that part anymore," said one of the make-up artists. "Mercedes, if you wouldn't mind?" the artist continued, gesturing for Nadine (or rather Mercedes) to sit down in a chair so that they could get started on her make-up. So what was Nadine's reaction? Was she like Sarah, thinking she was Nadine? Or did she believe that she was an actress named Mercedes, who thought that "Nadine Ferguson" was a part that she had been playing in a TV show or movie, and that she was now playing a completely different role? And what new role was she going to be playing?