- 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
Mark has captured Sarah and taken her to the Castor compound, where she is housed in a cell adjacent to Helena's. However, it's not quite the reunion that Sarah was hoping in that Helena will not forgive Sarah for turning her in, she unaware that it was actually Mrs. S who made the arrangement. Although Helena will not open up, Sarah knows that Helena knows the detailed workings of the compound and thus probably knows a way out. Beyond Helena, Sarah has to decide who she can trust, the list of people who includes Paul. Meanwhile, Cosima goes on her date with Shay, the two who met on an Internet dating site. There seems to be a connection between the two. Cosima, however, is unaware that there are more people on their date than meets the eye. And now that she has miscarried, Gracie has been shunned by her mother and excommunicated. Because of Sarah, Gracie turns to Art for help, he in turn who believes that Mrs. S and Felix are better equipped to look after her. Felix in particular is uncertain if they can trust who he refers to as "Rosemary's baby".