Biohorror and biothriller movies depict infectious diseases that are bioweapons or mother nature’s weapons where they lead to terror brought on by people, governments, enemies or nature. Quarantine, pandemic, laboratory creations and accidents, all provide plot-ready horror and action for this subgenre. Another indication that you are in this subgenre is the film title: Quarantine; Pandemic; Contagion; Outbreak; Contaminated; Waterborne; Carriers. All of these have served as titles, some more than once. These movies might be called the “petri dish movies” since they all involve a biological organism, like the “spaghetti westerns” referred to the Italian filming location of a subgenre of westerns.