Simon Nightingale is a typical doctor who's fresh out of Medical School and tries his best to better himself. However, things take a turn for the worst, when Xenos, a new type of creatures suddenly come to be and completely tear apart the known world. The protagonist managed to get by in such a world, until he was suddenly murdered. However, he was given a second chance; on more shot at doing this right, retaining all his prior knowledge. But this time, he has a 9-month period prior to the first day of the apocalypse to properly put together his plan. Will he win this race against the clock and the fight against those creatures?