At the Observatory, Mokrani and Catherine clash over the fate to be reserved for Micah, whom Catherine considers to be a major source of information. Micah reveals to Catherine that she has to find Bill Ward. The latter, for his part, tries to find out more about Emily, still assailed by visions of Adina, the leader of the aliens urging him to kill Bill.

Catherine, Sophia and Nathan make their way to London, accompanied by Victor, a survivor encountered by chance. Along the way, the dangers multiply. Sacha's feelings towards Emily intensify and the young man's behavior becomes more and more disturbing. Feeling threatened, Bill is forced to flee.