The Mortal Instruments
The Infernal Devices is a trilogy by author Cassandra Clare, centering on a race called the Shadowhunters introduced in her "The Mortal Instruments" series. The trilogy is a prequel series to "The" "Mortal Instruments" series, and contains some of the character's ancestors. Cassandra Clare has stated that the two series are able to be read in any order, but it is best to read in the order they were published to further understand the stories and avoid indirect spoilers.