Season 5, episode 5
Writer: J.H. Wyman
Director: PJ Pesce

Fringe worked one of its best themes — the dehumanization we risk by seeking to become superhuman to assuage pain and achieve justice — to shocking effect when Peter, raging from Dead Etta grief, butchered an Observer to jack his quantum computer/teleportation power plug and become an omniscient yet dangerously distant transhuman himself.