Fringe: Season 3, Episode 18

3 - 18: Bloodline

In the parallel universe, Fauxlivia is kidnapped and given a procedure to accelerate the birth of her child. As the Fringe division searches for her captors, Lincoln and Charlie learn that Fauxlivia and Olivia of the prime universe had recently temporarily swapped places, and become distrustful of Walternate. Ultimately, Fauxlivia escapes, and the Fringe division finds her in time to safely give birth to her son. It is revealed the process was all initiated by Walternate who obtains a sample of the child's blood after Fauxlivia is brought back safel