Starting where last season left off, the new trailer, which is an astounding three minutes long, starts with Brody and Carrie saying goodbye. Then, everyone has a breakdown.
In the trailer you see that Brody's family is a traumatized shell of what it used to be, Carrie is the subject of a Congressional investigation and then is chained to a hospital bed, Brody is in the Middle East somewhere full of bulletholes. Like 10 people get shot, and Brody wields a shotgun on the back of a truck. It's awesome.