"The Infernal Devices" is a young adult fantasy trilogy written by Cassandra Clare. Set in Victorian London, the series follows Tessa Gray, a young woman with the ability to shapeshift, as she navigates a world filled with Shadowhunters, demon-fighting warriors. The story explores themes of love, friendship, and sacrifice while introducing a rich cast of characters, including Will Herondale and Jem Carstairs. The trilogy consists of three books: Clockwork Angel, Clockwork Prince, and Clockwork Princess. It serves as a prequel to Clare's earlier series, The Mortal Instruments, and delves into the origins of the Shadowhunter world, showcasing the struggles against dark forces and the complexities of human emotions.