Cordelia Carstairs seems to have everything you could ever dream of. She is engaged to James Herondale, whom she has loved since childhood. Her best friend, Lucy Herondale, is nearby, as is her trusty sword, Cortana. And the father whom Cordelia loves so much finally returned home. But this is just a festive façade. In reality, everything is much darker. The marriage to James is a lie necessary to save Cordelia's reputation. Cortana burns her owner's hand as soon as she touches her. And my father’s return did not go at all as expected. London is also uneasy. A serial killer is stalking Shadowhunters in the dark streets of London... Many have already died at his hands. Cordelia, James and Lucy are trying to track down the killer and keep a secret - each their own, terrible, capable of irrevocably changing a lot.