The first official trailer for ‘Grey’s Anatomy’ season 12 has finally been unveiled and, as Meredith Grey (Ellen Pompeo) reveals, "You are about to find out that everything has changed."

First off, Pompeo’s character can be seen running through a messy hallway in her mother’s old house, where's she is presently living with Maggie (Kelly McCreary) and Amelia (Caterina Scorsone).

After the storyline of the series underwent significant changes with the unexpected death of Dr. Derek Shephered (Patrick Dempsey) at the end of last season, the hit ABC drama series was set for a transformation.

"We've seen the pitch for ‘Grey's Anatomy’ next season. The show reinvents itself again,” ABC executive Paul Lee assured fans at the 2015 Television Critics Association summer press tour.

Lee also echoed fans’ sentiments that Dempsey’s exit from the series had been a tough experience. Nonetheless, he added: "It was great to see [the show] so relevant and taking the national conversation.”

As for Pompeo, she compared ‘Grey’s Anatomy’ to the other TV programs also created by Shonda Rhimes, including ‘How to Get Away with Murder’ and ‘Scandal,’ to emphasize that the medical drama will remain a successful program even without McDreamy.

"It is, like, Annalise Keating carries the show," Pompeo said in an interview with Entertainment Weekly. "Olivia Pope carries the show. But, somehow, Meredith Gray needs someone. Why can't I just be the lead of the show the way Annalise and Olivia can? Why can't I be on that poster by myself?"

After coping with McDreamy's death, fans can look forward to the next season with a “lighter” tone.

"’Grey's,’ there's a much sort of lighter tone this year that we're going for. Meredith Grey has never been defined by her relationship with a man,” Rhimes stated.

The series creator has not yet made plans of coming up with a new romantic partner for Meredith in season 12 despite actor Martin Henderson signing on to the cast to play a new surgeon.

“Meredith is in a rebirth and she's evolving. I'm watching the character do what the character's doing and I'll see where it goes,” Rhimes told E! News.

‘Grey's Anatomy’ season 12 is set to premiere on Sept. 27 at 8 p.m. on ABC. Its first official trailer can be viewed below.