Although "Grey's Anatomy" season 11 ended with the untimely death of Dr. Derek Shepherd (Patrick Dempsey), the dark tone is apparently going away as the new season 12 promotional trailer focuses on a short, upbeat change of mood that promises "everything will change."

The trailer starts with a reminder that the premiere is getting closer while showing a few shots of Dr. Meredith Grey-Shepherd (Ellen Pompeo) resting in her bed. The alarm clock rings and the titular character makes a promise that things will change, hinting that strange days are forthcoming. 

After all, this will be the first season without Dempsey. The name Dr. Shepherd or even his moniker Dr. McDreamy are never mentioned in the trailer, hinting that the showrunners, cast and crew are moving forward without the need of lingering on his absence. 

The trailer then skips to showcase the doctors giving each other high-fives and to a sequence where Meredith sees her new roomates breaking her home's wall with a sledgehammer. There is also a point in the trailer where someone gets punched in the face in what appears to be a throwback to classic slapstick humor — something uncommon in the series.

As pointed out in a report from MovieFone, the music and overall tone of the trailer indicates that season 12 will be positive and lively, which may be a welcome change for the audience and the people working on the show. The report also states that this may be a new start or soft reboot for the series, which has no signs of slowing down.

One character not showcased in the trailer is Martin Henderson, who was recently cast as a new series regular. The actor will be portraying a new doctor in the show and it is heavily speculated that he will be Meredith's new love interest. 

"Grey's Anatomy" season 12 will premiere this Sept. 24 on ABC.