Passage Summary: Horror stories usually feature either mad scientists or monsters. While their themes differ, every horror story breaks the laws of nature and tries to scare the audience.

Reasoning: Horror stories are categorized into two types—mad scientists and monstrous beasts—both of which involve violations of natural laws and the intent to cause dread in readers.

Analysis: Since this is a 'Must be True' question, we are looking for a deduction that is logically guaranteed by the premises. The most powerful piece of information here is the overlap: regardless of the sub-genre, all horror stories share the traits of violating natural laws and intending to produce dread. Therefore, if a story lacks one of these traits—for instance, if it follows the laws of nature perfectly—it cannot be a horror story under this definition. Look for an answer that treats these shared characteristics as necessary requirements for the genre.