City of Glass is the third book in The Mortal Instruments series, an urban fantasy series set in New York written by Cassandra Clare. It was originally published in the United States in hardcover on March 24, 2009.PlotPicking up from City of Ashes, City of Glass begins a few days after Clary and Jace's awkward break-up. With the permission of the Clave and Alicante, Magnus Bane creates a portal to send the Lightwoods, Jace, Clary and Madeleine to Alicante. Desperate to keep Clary safe, Jace lures Simon to the Institute and asks him to lie to the Lightwoods about Clary not wanting to go to Idris. Simon refuses, but their argument over the issue is interrupted when the Institute is attacked by Forsaken. During the attack Madeleine is killed. Simon is seriously injured, which leaves Jace with no choice but to bring him through the portal as well or risk the Forsaken killing him.Clary arrives at the Institute to find it deserted. Magnus explains to her what has happened. Using her powers Clary creates a portal. Luke attempts to stop her, but instead both are dragged through to Idris. Since none will enter the city who are not authorized, they are thrown outside of the city into the surrounding fields, mountains blocking their path to Alicante. They land in a strange lake with odd reflective powers. Luke explains that they landed in Lake Lyn, which is the very lake that Raziel emerged from with the Mortal Cup and Sword, offering the instruments to Jonathon Shadowhunter (the first of the Shadowhunters). Lake Lyn has been cursed for all Shadowhunters since; the water is incredibly toxic and, if ingested, causes intense hallucinations and fever that could be followed by madness.