Fringe Season 3 Episode 4 - Do Shapeshifters Dream of Electric Sheep?

In the prime universe, U.S. senator James Van Horn (Gerard Plunkett) is hospitalised following a car accident. After Newton arrives and shoots him in the face, Broyles discovers Van Horn was in fact a shapeshifter, who collected data on Fringe Division. Walter discovers that Van Horn is still alive at some degree and has another "brain" in his back. Before Walter can get to it, Newton activates asleeper agent, Ray Duffy (Marcus Giamatti) to extract it. When his mission is complete, Newton learns that Ray has grown attached to his family and kills him. Then, Fauxlivia and Peter capture Newton following a car chase. Knowing it may blow her cover, Fauxlivia visits him and gives him a suicide pill that causes him to bleed out mercury. In the end, Fauxlivia invites Peter to her home and sleeps with him in an attempt to draw his attention away from his growing suspicion that something is not right with her.

Air date: October 14, 2010

Reference: http://en.wikipedia.org/wiki/Fringe_season_3