: A climactic showdown that confirms the existence of an alternate reality, ending with a view of the World Trade Center still standing in another New York.

La temporada tiene 20 episodios. Algunos destacables:

At its core, the season is anchored by its three lead characters. Olivia Dunham (Anna Torv) is the determined FBI agent whose personal trauma and professional integrity drive the narrative. She is complemented by Peter Bishop (Joshua Jackson), a brilliant but cynical polymath with a shady past, and his father, Dr. Walter Bishop (John Noble). Noble’s portrayal of Walter is the show's crowning achievement; he manages to be both a comic relief obsessed with root beer floats and a tragic figure haunted by the ethical boundaries he crossed in the name of "fringe science."