City of Glass Book by Cassandra Clare

Love is a mortal sin, and the secrets of the past are deadly. Plunge into the third installment in the internationally bestselling Mortal Instruments series and “prepare to be hooked” (Entertainment Weekly).

To save her mother’s life, Clary must travel to the City of Glass, the ancestral home of the Shadowhunters—never mind that entering the city without permission is against the Law, and breaking the Law could mean death. To make things worse, she learns that Jace does not want her there, and Simon has been thrown in prison by the Shadowhunters, who are deeply suspicious of a vampire who can withstand sunlight.