20. There's More than One of Everything

Complete story — includes the ending

Nina recovers from her attack and reveals to the Fringe Division that Jones stole an energy cell from her mechanical arm; he intends to use it to open a doorway into a parallel universe to confront William Bell. Meanwhile, Peter finds Walter at a beach house where they retrieve a device that can seal the opening. Walter once lost something dear to him and had to retrieve it from another reality, the device being meant to prevent something from following him. Olivia, Peter and Walter intercept Jones opening another window, and Peter triggers Walter's device, killing Jones by sealing the doorway while only half of him is through it. Walter later goes alone to visit a graveyard and cries while observing a gravestone marked "Peter Bishop 1978-1985," suggesting that Walter's legitimate son died. Nina later calls Olivia and implies that she can meet William Bell in Manhattan. Olivia is transported to the parallel universe and is directed to an office. After reading a newspaper headline indicating that President Obama was preparing to move into the "new" White House, she is greeted by William Bell ( Leonard Nimoy ) and inquires where she is. They turn out to be standing inside the South Tower of the World Trade Center.