Newer Elements of Our Defense (S03E04)

After Mark is wounded in a confrontation with the Proletheans, Sarah must take charge. As she collects vital information that could lead her to the original Castor DNA, an old adversary lurks nearby. While Helena endures hardships in a distant military facility, Sarah's own destiny becomes precarious as she strives to rescue her sister. Simultaneously, Gracie finds herself expelled from the Prolethean community, while Alison and Donnie encounter a furious drug lord, Jason Kellerman, face-to-face.