In a world ravaged by deadly mutations and radiation, Isim and the remaining human population dwell in a bunker deep underground. Isim has never seen the sun and may never do so. His only true wish is to find his father, who left him when he was too young to remember. He must brave the levels of the bunker to uncover the truth about his family and what lies beyond their underground sanctuary. Will he find his father, or will the harsh realities of the post-apocalyptic world shatter his hope for a reunion?