After the Mithraic kids fall sick, Campion believes Mother is poisoning them and plans an escape. As Mother and Father attempt to prove otherwise, Marcus and Sue work to convince the other surviving Mithraic to mount a rescue of the children, desperate to get their son Paul back.

Father tries to teach the children how to hunt some of Kepler-22b’s mysterious creatures for food. Meanwhile, the Mithraic make a stunning discovery that potentially fulfills a Mithraic prophecy, and a debate about how to proceed ignites a conflict between Marcus and the Mithraic leader, Ambrose.

Marcus’s decisions stress his relationship to his family as he struggles to maintain his clout as leader of the Mithraic. Mother is able to see Marcus for who he truly is, which threatens his power and puts Mother in a precarious situation she might not recover from. Meanwhile, Campion is faced with a choice that could result in dire consequences.

As Marcus continues to embrace his Mithraic devotion, Sue worries he may no longer have her and Paul’s best interests at heart. Meanwhile, Mother experiences what she believes to be malfunctions, and Hunter works on a secret project with Father.

Paul begins displaying troubling behavior not unlike that of Marcus, leading to a shocking discovery. Father struggles with human-like emotions. Mother and Father discover a startling secret about the planet they’re on, just as a new threat arrives on Kepler-22b.