The Infernal Devices is a trilogy by author Cassandra Clare, centring on a race called the Shadowhunters introduced in her The Mortal Instruments series. The trilogy is a prequel series to The Mortal Instruments series. Cassandra Clare has stated that the two series are able to be read in any order, but it is best to read them in publication order.The series follows Tessa Gray, an orphaned teenage girl who discovers she has the power to shape-shift but doesn't bear a Warlock’s mark. She is forced to learn how to control this newly established power and navigate the new world she’s been thrust into. The series follows Tessa's life as she lives in the London Institute with the Shadowhunters. The trilogy features William "Will" Herondale, James "Jem" Carstairs, Theresa "Tessa" Gray, and other Downworlders and Shadowhunters. It also features Magnus Bane, Camille Belcourt, and Woolsey Scott and other characters who appear in The Mortal Instruments series. The books also contain many quotes referring to famous pieces of Victorian Literature like Oscar Wilde's The Importance of Being Earnest, and the works of Samuel Taylor Coleridge and Alfred Tennyson. Source: Wikipedia (en)