Chain of Iron and Chain of Gold by Cassandra Clare

Brand New Chain of Gold Chain of Gold is a Shadowhunters novel. Cordelia Carstairs is a Shadowhunter, a warrior trained since childhood to battle demons. When her father is accused of a terrible crime, she and her brother travel to London in hopes of preventing the family's ruin. Chain of Iron Cordelia Carstairs — a young Shadowhunter about to enter into a false marriage with the man she secretly loves. She is the bearer of the sword Cortana, that burns her when she touches it, and must find a murderer who's killing Shadowhunters.