In the year 2013, Earth is attacked by an alien race that destroys the planet and puts an end to civilization. Three hundred years into the future, humans had migrated to a group of hidden caves located in the midst of the highest mountains. The story follows Jemma, a twenty year old who was born and lived all her life in the caves. But when one of the people closest to her is forced to leave, she is left with no choice but to venture on a dangerous journey that will reveal the most shocking truths about the aliens, about Earth and about Jemma herself.