Molly's baby is alive and growing. But Kern and Kryger insist that Molly wasn't its mother. She was just the "host," sent into space by her boss, Sparks, to be the vessel to bring the baby to Earth.
John accuses his assistant, Julie, of changing Ethan's programming so that his development cannot be slowed down. But Julie says she didn't touch anything. Is Ethan developing a mind of his own?
Meanwhile, Sparks meets with Yasumoto and tells him that Molly broke into their operation and then escaped. Sparks wants to kill Molly. She's too much of a threat. But Yasumoto forbids him. Molly is the mother of "the offspring" (code name for the baby). Perhaps the baby needs Molly to survive, even though they are separated. Once they know the offspring can survive on its own, only then can they eliminate Molly. Yasumoto also says that he's dying. "The substance," a life renewing force related to the offspring, is keeping him alive. They decide to move the offspring to a contingency site, aka a new location.
Molly goes to the ISEA to tell the truth about Sparks but Kern gets there before she has the chance. He tells her about Sparks' plan to move her baby. They must intercept it now, before it's too late.
Back at home, Ethan carelessly rides his bike without telling John where he's going. He meets up with two older boys who try and steal his bike. But when they see he's a Humanich, they run away. Ethan asks John what his function is - why is he here? Julie tells Ethan they made him to find his own function.
With Kern and Kryger's help, Molly breaks into the lab where they're keeping her baby. Sparks catches on to Kern - he knows Kern is playing both sides. Molly and Kryger break in. But when they reach the enclosed chamber that's keeping her baby alive, Kryger shoots it. The offspring is dangerous. He can't let it live. Molly opens the chamber to find - a guard, shot by Kryger. Where's her baby?
Sparks comes face to face with Molly. He didn't want it to end this way. But he needs to see his daughter again and this baby has a life-renewing substance that can make that happen. Sparks shoots Molly. But when he turns her lifeless body over, all he sees is his dead daughter, Katie.