City of Glass, the third novel in The Mortal Instruments series written by Cassandra Clare, picks up when Jace and the Lightwoods are headed to Alicante, the homeland of Shadowhunters, and Jace tries adamantly to keep Clary away from the by trying to convince Simon to lie to the Lightwoods about Clary not wanting to go, because he feared the Clave they may try to use her as a weapon.
When they are attacked by a group of Forsaken, Simon is seriously injured and is brought to Alicante by Jace and is taken prisoner by some Clave members because he refuses to lie and say that he and the Lightwoods are spies for Valentine.
When she finds out that they’ve left without her, Clary makes her own portal which takes herself and Luke close to Alicante. After Clary ingests water from Lake Lyn, which causes hallucinations and death if the someone drinks the water, Luke brings Clary into the city secretly and to his sister, Amatis.
While in Alicante, after being nursed back to health by Amatis, Clary sets out to save her Mother from the spell that she put herself under. Along with Sebastian Verlac, she goes in search of Ragnor Fell and ends up finding Magnus Bane instead. Magnus tells Clary to go and find a spell book in the Wayland manor to break the spell on her mother.
After Clary comes back with the spell book, to find Alicante in flames and the barriers that keep the demons out are down. During the demon attack, the Lightwood’s youngest son, Max, is killed and Clary, Jace and Alec break Simon out of jail.
Clary convinces the Clave to join forces with the Downworlders after Valentine threatens them with an attack, or giving themselves over to his service. During a conversation with her Mother (who was woken up by Magnus once Clary gave him the spell book), Clary finds out some very important information about her and her brother.
One of the most important things being that Jace is in fact, not her brother.
By the end of the book, Valentine is finally defeated by the Angel, Raziel, who sees through Valentine’s lies and schemes as clearly as night and day. Clary is offered one wish, and she asks for the angel to bring back Jace because Valentine had used Jace as sacrifice to call the Angel to Lake Lyn.
This book was interesting, because it’s the first time in either of the series that they actually go to Alicante instead of just talking about it. It’s all Shadowhunter’s home, and they miss it even if they’ve never been there or haven’t been there in forever.