The situation at the London Institute has never been more precarious. With Mortmain and his clockwork army still threatening, the Council wants to strip Charlotte of her power and hand the running of the Enclave over to the unscrupulous Benedict Lightwood. In the hope of saving Charlotte and the Institute, Will, Jem, and Tessa set out to unravel the secrets of Mortmain's past.

Cassandra Clare is the author of the #1 New York Times, USA TODAY, Wall Street Journal, and Publishers Weekly bestselling Shadowhunter Chronicles. She is also the coauthor of the bestselling fantasy series Magisterium with Holly Black. The Shadowhunter Chronicles have been adapted as both a major motion picture and a television series. Her books have more than fifty million copies in print worldwide and have been translated into more than thirty-five languages. Cassandra lives in western Massachusetts with her husband and three fearsome cats. Visit her at CassandraClare.com. Learn more about the world of the Shadowhunters at Shadowhunters.com.