'Grey's Anatomy' Season 21 Teaser: Tensions Rise at Grey Sloan

The new season picks up with job uncertainty, returning characters, and escalating conflicts.

Season 21 of 'Grey's Anatomy' premieres on September 26 at 10 p.m. on ABC.
The trailer shows Catherine Fox clashing with Miranda Bailey, leading to a dramatic slap.
Meredith Grey, who resigned over Alzheimer's research, will appear in seven episodes.
Fan-favorites Jackson Avery and Sydney Heron return, adding to the unfolding drama.
New season introduces a gay chaplain and a childhood friend of Owen and Megan Hunt.