In Which We Meet Mr. Jones - S1-E7
Visible crew/equipment: During the shot where Walter is talking about Jimmy Hoffa while installing a light bulb, you can see the set and crew reflected on the metal part, including the audio coordinator with a boom mike.
Answer: In the time line of Season 4, William Bell is trying to destroy both universes to create a new one, and he needs Olivia to power the collapse. So he helped her escape. But the real question is, if not in search of Peter, why Olivia has to travel to the alternate universe to be captured and replaced?
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