A virus is unleashed into the air, rendering it deadly to humans. Among the survivors: a detective whose addiction to the drug known as 'Filter K' takes over his life; a brother and sister who, due to recent events, start to wonder if the air really is deadly, or if it's all just a conspiracy; a mother and daughter who will do anything to keep their family together; and a breather salesman who is looking to make amends for his past mistakes. They are all survivors of this virus-plagued world. They are all 'breathers.'