In the future, the atmosphere of Earth becomes toxic destroying the civilizations. There is an exodus of the survivors that leave the planet to a space station on the gravity of the moon of Jupiter Io. The scientist Henry Walden and his daughter Samantha "Sam" Walden stay behind researching a means to save Earth from dying. Sam is researching bees expecting them to survive in the atmosphere to pollinize the plants. She thinks in the possibility of leaving Earth on the last shuttle to Io to meet her boyfriend Elon that has left Earth to live in the station. Out of the blue, there is a storm that destroys her camping and research. Soon a balloon lands and the pilot Micah asks for Dr. Walden, but Sam explains that her father is not in the camp but researching the nearby field. Micah decides to wait for him and on the next day, Sam confesses that her father died. He convinces her to travel in his balloon to the shuttle but soon they learn the launching place changed and Micah does not have enough helium to reach the spot. Meanwhile Sam learns that Elon was assigned to a ten-year voyage to Alpha Centauri and they will never see each other again. What will Sam do?