"Grey's Anatomy" season 12 will feel brand new when it officially fires up on Sept. 24. In the latest teaser for the upcoming McDreamy-less season, fans will learn that "everything has changed" inside Grey Sloan Memorial Hospital and beyond.

Meredith's life will never be the same after Derek's death. While it was suggested previously that this is not at all a bad thing for the character, it won't be easy either.

In the premiere episode titled "Sledgehammer," this transformation starts as Meredith moves into her childhood home with her sister-in-law Amelia and her sister Maggie, whose idea of mornings and alarm clocks apparently includes smashing a hole into the wall. This is the first thing she will have to adjust to.

Clearly, these three women have different personalities and interests. With that, it is easy to imagine chaos ensuing with them together under one roof. This is especially true for Maggie, who, in the trailer, punches a woman in the face.

While "Grey's Anatomy" season 12 will see Meredith struggling to accept the fact that her husband is no longer with her, the new season, as series creator Shonda Rhimes has long reiterated, will not show this with a brooding approach. Instead, the new season will take on a lighter tone. This should easily manifest considering how melancholic things ended in season 11. Here, Meredith will realize that she is also special and that she deserves great things, too. And so fans will also see her strive for those things. 

"We were telling volatile stories, and this year we're going to turn over the soil, and the show has a lighter look. It's brighter. We're trying to go back a little bit more to the original Grey's and have a little bit of a lighter tone this year," Ellen Pompeo, who plays Meredith, told Entertainment Weekly.

"Grey's Anatomy" season 12 premieres Sept. 24 on ABC. It can also be viewed online via live stream on ABC.com