Mrs. S and Sarah team up to investigate a lead on a Neolution defector. Elsewhere: an unexpected reunion takes place on the island and Cosima makes a terrible discovery during her research.

Cast: Tatiana Maslany, Jordan Gavaris, Kevin Hanchard, Kristian Bruun, Ari Millen, Josh Vokey, Maria Doyle Kennedy, Skyler Wexler, Rosemary Dunsmore, Stephen McHattie, Jenessa Grant, Lauren Hammersley, Cynthia Galant, Sirena Gulamgaus, Pip Dwyer