Greys Anatomy -: Season 12

: This season marked the final regular appearance of Sara Ramirez as Callie Torres. Reception & Ratings

: Tension peaks when Callie’s new girlfriend, Penny, is revealed to be one of the doctors who failed to save Derek. Penny eventually joins the hospital as a resident, causing friction with Meredith and Amelia. Relationship Turmoil : Greys Anatomy - Season 12

Season 12 of Grey's Anatomy , which premiered on September 24, 2015, is often described as the "season of rebirth". Following the death of Derek Shepherd in Season 11, the show shifted to a noticeably lighter, more "rom-com" tone, reminiscent of its earliest seasons. : This season marked the final regular appearance

: Meredith Grey adjusts to life as a widow, moving back into her mother's house with her "sisters," Maggie Pierce and Amelia Shepherd. A major mid-season arc involves Meredith being brutally attacked by a patient, leading to a long recovery and therapy. Relationship Turmoil : Season 12 of Grey's Anatomy

: A bitter custody battle over their daughter, Sofia, ensues when Callie plans to move to New York with Penny.

: Jason George (Ben Warren) was promoted to a series regular. Giacomo Gianniotti (Andrew DeLuca) also became a regular mid-season.