- 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
Cosima takes a turn for the worse, forcing Sarah to take desperate action - with tragic consequences for those she loves. The Proletheans set their ultimate plan in motion. Alison and Donnie tangle with the law.