Picking up where the "season finale" left off, Emily and Susan are on life support after being contaminated with a virus, which is found to be from a Purist group. The Purists have created a mass of it to spray over LA to kill all Newcomers. At the same time, an elite Overseer arrives to organize the return of the Tenctonese to slavery, and decides to take the human population as well. (thetvdb.com)