- Writers: John Fawcett, Graeme Manson, Alex Levine, Kim Coghill, Andrew De Angelis, Jeff Detsky, Adam Higgs, Bob Mackowycz Jr., Elize Morgan, Peter Rowley, Rebecca Sernasie
- Stars: Ari Millen , Dylan Bruce , Evelyne Brochu , Jordan Gavaris , Josh Vokey , Kevin Hanchard , Kristian Bruun , Maria Doyle Kennedy , Skyler Wexler , Tatiana Maslany
On information from Art, Sarah learns that it is not Rachel who abducted Kira, but rather the Prolethians, the reasons she does not know behind the abduction. However, there is no news whatsoever about Mrs. S, who she believes must have also been abducted along with Kira, which is only of little concern to her based on what her birth mother told her before her death. Regardless, Sarah decides to trust Art so that he can help her locate Kira. What Sarah discovers in the matter is not quite what she expects, which results in her not knowing who to trust. Art also tries to convince Angela to leave matters alone as he is not prepared to tell her everything that Sarah has told him. The Prolethians are also able to recapture Helena. Cosima tries to convince Leakie that she is not working with Sarah - that Sarah is indeed the enemy - and thus had nothing to do with Sarah infiltrating the event at Dyad using her identity. Cosima runs into a roadblock in taking over the research into her own biology, but is provided another task concerning the biology of the clones as a collective, but which focuses on Sarah. Felix is able to convince Alison that it is Donnie who is her monitor and not Aynsley. This news places Alison in a bad state as she deals with her involvement in Aynsley's death, but she and Felix also know that they need to catch Donnie in the act as conclusive proof.