Act I: (Voiceover of a woman). The Earth's atmosphere has turned-not just heated by climate change, but turned to poison. The vast majority of earthlings remaining flee in 100's of "Exodus" rockets to a space colony near Io. Switch scenes: person rides up in an ATV with an oxygen mask. Closeup shows the face of a woman. She enters a subway area, takes unusual samples from standing water while talking into a recording device. Then she drives away; up, up, up above the clouds to what looks like an abandoned lab with large telescope. Act II: Everyday life of Sam, whose name is revealed when she writes a tender e-mail to Elon, who is obviously her love. Elon is at the space station near Io. He asks about Sam's father, and encourages her to get both of them on an Exodus flight to leave earth. Sam grows vegetables-note that plants may or may not be affected by atmosphere-and makes trips down to the Zone for samples. In her down time, she reads a mythology book she took from an abandoned library, checks her wind turbines and solar panels, and every day plays a cassette tape with her dad's voice intended as a radio broadcast. She also has a recurrent dream she has where she is standing on beach, breathing normally. One day she goes to the Zone and see a massive thunderstorm coming. She rushes to return to the lab, only to find the wind turbines and solar panels damaged, and her lab where she tests samples destroyed. The greenhouse is relatively intact. Another email from Elon tells Sam that Command is putting all its resources into a mission to transport earthlings to another star that is 10 light years away. The last of the Exodus transports will be leaving in four days. Soon after that, a balloon shows up at the station. Out of the balloon capsule steps a man. Sam is standing there, just watching. The man walks up to her and says very clearly that he is looking for her father. She says she is his lab assistant, that he is out on a mission and should return soon. They make introductions; his name is Micah. Now the survival activity is Sam and Micah's. He continues to demand to see Sam's "boss"; Sam keeps stalling. Eventually, Sam confesses that her dad is dead. Mid-Act climax. Sam receives an email from Elon. She starts by saying that her dad is dead. Elon responds with condolences and then life-changing news: he has been asked to join the star mission and he has decided to go. He says their love can remain across the universe even as he leaves to a destination that is ten years away. Again, he urges Sam to leave on Exodus. Sam is visibly upset. She behaves strangely, even seducing Mikah. Mikah tells Sam that he will be taking her with him. He charts out the balloon's trip to meet the Exodus mission. Later, it turns out the location has changed and they won't have enough Helium. Sam says she knows where some is in the Zone. They leave, balloon in tow, for the Zone to get fuel so that they can launch the newly-filled helium balloon from a city park. They get the helium to fill the balloon but Sam feels compelled to visit the final art exhibit that was installed in a museum in the Zone before they leave that she had alluded to earlier in the film. Micah reminds her that she only has one hour before they need to depart. Act III: Sam in the museum. When Sam does not return within the hour, Micah goes to the museum to track her down. The scene before shows her fascinated by the exhibits, yet her face is troubled. There Micah sees Sam looking at a painting of Leda and the Swan and she reads from the description beside of it but doesn't initially understand so she asks Micah to teach her the meaning. Micah outlines this classic Greek myth. Sam appears to understand how it applies to her and the future of the earth providing vision and hope to Sam. Sam tells Micah that she has been having the same dream over and over about lighting a flame that burns dark purple (indicates insufficient oxygen to sustain human life) but that she can breath this new air in her dream so rather than replacing her oxygen canister, she removes her mask and inhales. Micah catches her in his arms (his mask remaining in place). In the epilogue we learn that her prior conditioning was effective resulting in her ability to breathe this "new" atmosphere. She tells him she will not leave; that Earth can be saved. Epilogue: Sam standing on a misty/foggy beach with a Micah's child. Sam's voice over of email to Micah, encouraging him to bring people back to Earth as they can survive as she and her son have done and invokes recognition of her father quoting TS Elliott as to how we all come back to where we once started and its all new to us once again