The Underwoods and their team angle to undermine the revived committee investigating Frank. Hammerschmidt's investigation heats up.

Frank attempts to stop Cathy from testifying. With Hammerschmidt sniffing out the truth, the Underwoods throw someone close to them under the bus.

In the wake of a surprising announcement, everything at the White House is shaken up. A decision must be made about whether to go to war.