Julie Sharbutt

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.

Office politics come to a head when Will and Diane ask Alicia and Cary to face off against them in a mock trial, only to get more than they bargained for. Meanwhile, Eli tries to avoid losing his role in Peter's campaign to Jordan, as he continues his fight with the Justice Department.

On the night of Peter's gubernatorial election, Alicia, Will and Diane race to a series of emergency court proceedings when Zach believes he's witnessed vote tampering. Meanwhile, an unlikely source offers Cary aid to start his own firm, while the conflicted feelings Alicia has in her personal and professional lives come to a head, on the fourth season finale. Martha Plimpton, T.R. Knight, Denis O'Hare, Dylan Baker, Ana Gasteyer and Estelle Parsons guest star. New York City Mayor Michael Bloomberg appears as himself.

A teenager (Astro) whose brother was recently murdered is identified as the latest person of interest; Finch fears that his ex-partner's son is getting close to discovering the machine.