Homeland aired what could have been a season finale on Sunday. Multiple truths were exposed, the game was legitimately changed and a new threat emerged to conclude a terrific episode.

So where does the Showtime drama go from here?

On next week's "Achilles Heel," Carrie and Saul will scramble to track down Walker, while the CIA and the FBI clash over how this can be best accomplished. Meanwhile, Brody aims to track down a mysterious man who may possess intel about his years as a POW. Watch the official preview now and just try to back off the edge of your seat:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.