Achilles Heel

S1 E8: Carrie and Saul scramble to locate Walker after discovering that he's alive and working with al-Qaeda. They must also deal with competing intelligence agencies' disagreements over the best way to chase him down. The FBI wants to enlist the public's help, but Carrie prefers a more personal approach. Meanwhile, Brody chases down a mystery man who reveals a shocking truth behind his eight long years in captivity.