S4, E15: When the Justice Department refuses to reveal who will testify against Eli, Elsbeth takes Assistant U.S. Attorney Josh Perrotti to civil court for defamation in order to force him to answer her questions under oath. Meanwhile, Jordan helps Peter prepare for a debate and Alicia's relationship with her co-workers evolves. Carrie Preston, Kyle MacLachlan, Amanda Peet, Maura Tierney, T.R. Knight, Dominic Chianese and Lily Rabe guest star.