It's Cristina Yang's week in the new episode of "Grey's Anatomy". In "All by Myself", she is awarded the first solo surgery among the residents but must give it up and choose for her replacement. Meanwhile Mark performs a cutting edge procedure to restore a patient's ability to speak, and impresses Lexie in the process. Also, Callie can't figure out if Sadie is just friendly or flirtatious. "All by Myself" is airing December 4 at 9/8c on ABC. Kevin McKidd is back as Dr. Owen Hunt, Cristina's new love interest while Melissa George is guest starring as Sadie, Callie's possible new lover. Academy Award nominated actress Mary McDonnell also joins the show as Dr. Virginia Dixon, a cardiac surgeon who suffers from Asperger's syndrome, a form of autism that causes an inability to interact socially with others