Twenty-three months after everyone thought she died on her final space mission. Katie Sparks reunites with her former flame, Sean, boarding the Seraphim. Sean is shocked. He thought she was dead.Meanwhile, back at ISEA, Molly has Sparks captured. But Molly can't get the truth out of him, even when she shows him a picture proving that his wife is dead. Sparks is convinced that the offspring will bring his wife, Anya, back to life. The offspring will fix everything – and end all of life's suffering. Suddenly, ISEA loses contact with the Seraphim. What's happening aboard that ship? And did Molly somehow send it off course?Meanwhile, Odin tells Ethan that his parents "don't really see you as part of the family." They're trying to shut Ethan down. Ethan's not sure who to believe, but he needs a friend. Odin gives Ethan a special emergency phone, for Ethan to get in touch with him if anything ever goes wrong in the lab. Now Odin can keep tabs on Ethan, giving Odin the upper hand.Molly asks her friend Sam to inject a memory enhancer into her neck, so she can bring back memories she's lost. Maybe then she can figure out how the codes she entered during a vision sent the Seraphim off course. Molly realizes her code was actually a warning message. But now the Seraphim is hurtling towards Earth. Without intervention, it'll disintegrate when it reaches Earth's atmosphere, killing everyone on board. Including Sparks' daughter, Katie.Back at the lab, Julie and her coworker try to figure out what's happening with Ethan but he's resistant to a shut down. Will Julie finally realize Odin's evil intentions?At home, John becomes infected by the offspring; the same strange circular pattern that afflicted so many now appears on John's neck. He has a vision of Molly, but she's not real. The real Molly is in the kitchen, surprised by a young child at the door - her first encounter with her baby (now a young boy), the offspring.Julie sneaks into Odin's apartment and finds out the truth. Odin's working against the Humanichs. And taking control of Ethan is step one. She rushes to John and Molly's house to warn them. But it's too late. Molly's missing. And so is Ethan.Molly catches up with her boy, who's hiding outside. She asks him why he's scared. The offspring says he's scared of "those without blood." Molly pleads with the offspring, stop "them" from coming to earth. But it's too late. Only Molly can stop the extra-terrestrials from invading Earth. And she must go back to space for one final mission to stop them.