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.