The teaser hints that Catherine Fox (played by Debbie Allen) is on a mission to rebuild the hospital after everyone's jobs were left in the dark in the previous season's finale.
In the final moments of season 20, Miranda Bailey (Chandra Wilson) places herself in the line of fire along with Catherine to protect her interns. And in the trailer released this week, Bailey isn't done yet and slaps Catherine in the face when she calls her "a regular doctor."
Meredith (Ellen Pompeo), Amelia (Caterina Scorsone), and Teddy (Kim Raver) are also on the run after Teddy agreed to continue secretly funding the Alzheimer's research that Catherine had tried to stop. It looks like Meredith will enlist the help of her son Jackson Avery (Jesse Williams) to get back into her good graces, according to the trailer.
Although they don't appear in the teaser, expect the return of Scott Speedman, who plays Meredith's boyfriend Nick Marsh, and Ben Warren in season 21. Kali Rocha will also reprise her role as Sydney Heron, 17 years after she last appeared on the show.
Season 21 drops on September 26 at 10 p.m. on ABC. Watch the new teaser below: