Not every killer can be caught using conventional methods. When crimes are committed that are supernatural in nature, different methods must be employed, methods that can match, outwit, and ultimately stop these unnatural perpetrators. The UPD is the FBI's answer to this need. Dianna Saferstein is new to the department, and until recently didn't believe in magic, monsters, or faeries. Now she must work alongside mages, shapeshifters, and a tech-savvy gremlin in order to stop supernatural mass murders and protect the human populace of Texas. But even though she's now in the know, not everything is as it seems. When dealing with the occult, there is always another mystery to untangle and danger around every turn. Unnatural Perpetrators, Texas Case Files 1.1-1.3 gathers three novellas and a short story detailing the perilous adventures of the FBI's elite UPD team based in Houston Texas. Contains: Inhuman Error, Artifice of Flesh, The Pleasant Folk, and Justice Incorporeal.