blood to activate the machine to destroy the other universe. For several episodes, Torv also played a third role, that of Olivia possessed by the mind of William Bell, which has been dubbed "Bellivia" by reviewers. In this, she simulates Nimoy's raspy voice and mannerisms used in the portrayal of Bell. Peter Bishop Peter Bishop (portrayed by Joshua Jackson as an adult, and Quinn Lord, Nico Ghisi and Chandler Canterbury as young boy; main: season 1–5) is the son of mad scientist Walter Bishop, and a member of the Fringe division. In the show's second season it is revealed that Peter is actually from a parallel universe from where he had been kidnapped by Walter after this universe's version of Peter died at a young age. He is a genius with an I.Q. of 190, a college drop-out with gambling debts, and a jack-of-all-trades. In the second season two-part finale "Over There", and a major plot element of the third season, Peter is found to be the only person that can cause a reaction from an apparent doomsday device that Walternate has assembled in the parallel universe and that is currently being assembled in the prime world. Walter Bishop Walter Bishop (portrayed by John Noble; main: season 1–5) is a former government researcher into fringe science with a recorded I.Q. of 196. He was institutionalized after a lab accident which resulted in manslaughter charges. Having been locked up for 17 years in a mental institute prior to becoming assigned to the Fringe division, Walter often expresses wonder at modern technology, and seems to be disconnected from the world, sometimes leaving his son to decode his rantings for others. He often says things which seem so obvious that no one else wants to say (or thinks necessary) and tends to burst into song while working, as he believes it helps him think. He is also known to eat or drink while working on a body, no matter how disgusting everyone else thinks it is. He seems to derive joy from both these quirks. He is the archetypal mad scientist. The Other Universe version of Walter Bishop, nicknamed , is the United States Secretary of Defense, and directly oversees the alternate and more powerful Fringe division. He is the main antagonist of the third season. Walternate also serves as the immediate superior to the shapeshifters, with their leader—Thomas Jerome Newton—being extremely loyal