"Infernal Devices" refers to a series of three novels by author Cassandra Clare, set in the Shadowhunter universe. The books—"Clockwork Angel," "Clockwork Prince," and "Clockwork Princess"—follow the adventures of Tessa Gray, a young woman with the ability to shapeshift, as she navigates the dangers of Victorian London and the world of demons and shadowhunters. The series explores themes of love, friendship, and sacrifice, while introducing key characters such as Will Herondale and Jem Carstairs. It serves as a prequel to Clare's earlier series, The Mortal Instruments, and delves into the origins of the shadowhunter society and their battles against dark forces.