Jem Carstairs is a fictional character from Cassandra Clare's series, particularly known in the Infernal Devices trilogy. He is a Shadowhunter, a member of a group dedicated to protecting humanity from demons and other supernatural threats. Jem is characterized by his kind nature, intelligence, and strong moral compass. He has a unique heritage, being of both Chinese and English descent, which adds depth to his character. Jem is also notable for his bond with Will Herondale, his parabatai, a term used to describe a close warrior partnership in the Shadowhunter world. He suffers from a chronic illness, which influences his perspective on life and relationships. Throughout the series, Jem's loyalty and compassion shine, making him a beloved character among fans.