Sixteen-year-old Clary continues trying to make sense of the swiftly changing events and relationships in her life as she becomes further involved with the Shadowhunters and their pursuit of demons and discovers some terrifying truths about her parents, her brother Jace, and her boyfriend Simon.

"Seventeen-year-old Kennedy Waters discovers she is a member of an ancient secret society formed to protect the world from a powerful demon determined to find a way out of his dimension and into ours. She joins the Legion on a mission to find a weapon that can defeat the demon"--Publisher.

Josh has chosen to side neither with his twin sister Sophie nor Nicholas Flamel, but rather to fight alongside Dr. John Dee and Virginia Dare, while the immortal Machiavelli and Billy the Kid plan to set loose the monsters of Alcatraz on San Francisco.

Nicholas Flamel and teenaged twins Josh and Sophie Newman return to San Francisco where a weakened Flamel reunites with his wife, Perenelle, hoping to use his remaining power to prevent the monsters on Alcatraz Island from escaping. Meanwhile, Dr. John Dee and Machiavelli continue to seek power and the twins desperately try to determine who they can trust as they search for Scatty and an immortal who can teach Josh the magic of fire.