Fringe: Season 2, Episode 15 - ProjectFreeTV

2 - 15: Jacksonville

After a building in Manhattan is destroyed after it merges with the same building from an alternate world, Walter believes another building of the same mass will disappear, along with anybody inside it. In order to uncover which building, the team rely on Olivia's ability to recognize objects from the other dimension. When she can't, they travel to Jacksonville, Florida, where Walter experimented on her and other Cortexiphan subjects. There, Walter discovers Olivia can find the building if she feels fear, which she is no longer able to do, however, upon returning to Manhattan, Olivia becomes afraid for not being able to save the people, and is able to use her ability again. After evacuating the building before it disappears, Olivia visits Peter and Walter's house. Because of her ability, she realizes Peter is from the alternate world; Walter pleads with Olivia not to tell Peter.