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.
As Clary uncovers more about her family's past, she finds an ally in mysterious Shadowhunter Sebastian. With Valentine mustering the full force of his power to destroy all Shadowhunters forever, their only chance to defeat him is to fight alongside their eternal enemies. But can Downworlders and Shadowhunters put aside their hatred to work together? While Jace realizes exactly how much he's willing to risk for Clary, can she harness her newfound powers to help save the Glass City - whatever the cost?
Love is a mortal sin and the secrets of the past prove deadly as Clary and Jace face down Valentine in the final installment of the New York Timesbestselling trilogy The Mortal Instruments.
(Cover and description taken from Goodreads)
The third Mortal Instruments book is even better than the first two, as the Shadowhunters face their toughest battle yet. The fight moves to Idris, the Shadowhunters’ home country, where Valentine intends to find the final Mortal Instrument in order to complete his plan to eradicate all Downworlders and destroy the Clave.
Clary wants to travel to Idris to find a cure for the enchanted sleep her mother is under, but Jace, Isabelle and Alec insist that it’s too dangerous, and persuade her best friend Simon to stop her. But when the Institute is attacked by demons, Simon is unintentionally dragged through the portal too. As a newly turned vampire, a Downworlder, he is not allowed into the city, but finds himself under scrutiny by the new Inquisitor due to his ability to stand in direct sunlight without being burnt- a side effect of consuming Jace’s blood. Distrusted by Shadowhunters and Downworlders alike, Simon is tricked into coming to the Hall of Accords, where he expects to be returned to his own world- but is instead imprisoned. The new Inquisitor intends to coerce him into speaking out against the Lightwood family, blaming them for the mistakes of the previous Inquisitor and for the success of Valentine’s plans.
Meanwhile, Clary makes a portal to Idris herself, using her power to create new runes, an ability no other Shadowhunter has. In doing this she unintentionally drags Luke, a werewolf friend of her mother’s, along. Alicante, city of the glass towers, is an impressive place, but the other Shadowhunters are unwelcoming, and she is frustrated by her failure to save her mother. In their search for the Gray Book, a book of immense power, Clary and Jace discover the true nature of Valentine’s past, and the reason his children can do things no other Shadowhunters can.
With two of the Mortal Instruments in his possession, Valentine is ready to declare war against the Shadowhunters, in the heart of their supposed haven. Clary and the others must convince the Clave that they should be fighting alongside the Downworlders, and not against them. But with betrayal at every corner, friends becoming enemies, and Valentine’s most diabolical plan about to succeed, who can truly be trusted? Whilst Jace struggles to accept that his father turned him into a monster, a weapon, and that the only way to free himself is to murder him; Clary realises that her talents could help ensure victory over Valentine and his demonic minions.
What I love about this series is that there’s something for everyone: forbidden love, fantastic action sequences, fantastic characters and unexpected plot twists. Love, loss and sacrifice culminate in a nail-biting climax to the trilogy. Cassandra Clare pulls no punches, and the finale is as heart-wrenching as it is gripping. The nonstop action and the astonishing revelations that, when you stop and think about it, make perfect sense, make this a thrill of a read from start to finish. A book that can keep me up reading all night is a winner in my book, and it was impossible to sleep without knowing the ending to this fantastic series.