97 years ago nuclear war killed all on earth, left it soaked in radiation. But there were survivors. Now there's the Ark, one station forged of many. Earth needs 100 more years to be habitable again and man can go home, back to the Ground. That's the dream. Not anymore. Failure in the life support is found, leaving the Ark not little time to repair it. In efforts to get time, 100 prisoners are sent to the Ground to see if it's survivable. But it's been fine all along. The Grounders are Earth's native people since the bombs and they won't take kindly to Sky People invading their home. The mission is much harder than they thought. Each kid has a story. Elektra Gale's father was floated for teaching his her as a skilled warrior when she wasn't even to be a guard. Too dangerous for Ark society, she's locked up and sent to the Ground. The fighter needs her skills more than ever to survive the cruel Earth. She must fight a war and for what she deems right, even siding with the enemy.