The year is 2167, earth has been uninhabitable for 100 years. All that is left of humanity has moved onto one massive spaceship in space. Finally, this year, scientists have deemed it possible for life to re-exist on earth again. But first, they want to ensure the earth is safe, so they are sending 100 teenagers below 18 back onto earth. Their mission is to radio back to the spaceship if it is safe. Katie, her best friend Logan, and Katie's long-time crush Elijah Hudson have been chosen as part of the 100 teens back.