"Clockwork Angel" is a young adult fantasy novel by Cassandra Clare, set in the Shadowhunter universe. It follows the story of Tessa Gray, a young woman who travels to London in the 1870s to find her brother. Upon arrival, she discovers she has the ability to shapeshift and is drawn into a world of supernatural beings. Tessa is taken in by the Shadowhunters, a group dedicated to protecting humanity from demons. She becomes entangled in a conflict with the Mortal Instruments and faces challenges from the mysterious Magister. The novel explores themes of love, identity, and the struggle between good and evil.