Ninety-seven years ago, nuclear Armageddon decimated planet Earth, destroying civilization. The only survivors on orbiting space stations are now exiling a group of 100 juvenile prisoners to the Earth's surface to test whether it's habitable. For the first time in nearly a century, humans have returned to planet Earth.
Octavia leads her people towards Shallow Valley against the advice of Clarke and Bellamy. Meanwhile Kane (series star HENRY IAN CUSICK) and Abby (series star PAIGE TURCO) adjust to a new set of challenges.