While the previous two Homeland season three trailers left us with more questions than answers, this latest teaser actually helps us discern what the plot might be. The teaser treats us to actual dialogue from the three main characters. We see Brody's confession tape from the first season, Carrie testifying that she believes Brody is innocent in that whole CIA car bomb thing, and Saul saying he won't "throw Carrie under the bus" but then testifying that she's unstable.
Basically, it seems season three — excluding whatever the Brody family is doing (eating more huevos rancheros?) — will focus a lot on the relationship between Carrie and Saul. He loves her, but ultimately knows she's a total loose cannon. (Perhaps that betrayal accounts for the "I am so sorry" in the previous trailer.) Or something like that.
One thing is for sure. There will be more Brody and more crazy eyes from Carrie. Carrie's crazy eyes nearly match her beautiful quivering jaw.