The Infernal Devices - Wikipedia, the free encyclopedia en.wikipedia.org/wiki/The_Infernal_Devices The Infernal Devices is a series of novels by author Cassandra Clare, centering on a race called the Shadowhunters introduced in her The Mortal Instruments series. This series takes place in Victorian England, ten years after the peace treaties between the demon-fighting Shadowhunters and Downworlde