Art student Clary Fray's life is turned upside down when she discovers that she is a Shadowhunter and part of a hidden world on the brink of war.
Determined to restore her lost memories, Clary and her new Shadowhunter allies enlist the mysterious Silent Brothers.
After the New York vampire clan kidnaps Simon, Jace trains Clary so she can join them on the rescue mission.
Clary enlists the help of mysterious warlock Magnus Bane to summon the demon that has taken her memories. A deep secret is revealed about Alec.
Clary, Alec and Simon look for clues that will lead them to Valentine, until Clary and Simon run into the New York werewolf pack.
As a wounded Luke fights for his life, he reveals to Clary the secret history between him, Jocelyn and Valentine.
The Shadowhunters know where the Mortal Cup is hidden, but a police precinct full of suspicious mundanes and shape-shifting demons stand in their way.
Clary ponders whether to resurrect Simon as a vampire. At the Institute, the appearance of Clave envoy Lydia Branwell forces Alec to make a sacrifice.
The Shadowhunters are divided over Lydia's decision to take Meliorn to the City of Bones for questioning. Simon struggles to control his new powers.
A portal will lead Clary right to Valentine, but first she must navigate a tranquil alternate reality where Shadowhunters no longer need to exist.
Clary and Jace team up with Michael Wayland, Jace's long-presumed-dead father, to save Jocelyn from Valentine, but Clary is suspicious of Wayland.
Alec grapples with his true feelings for Magnus. Clary and Jace deal with a surprising revelation as they seek help to break the spell over Jocelyn.
Clary's last shot at waking her mother up means she must turn to an old enemy for help. Jace deals with Hodge's betrayal and wages an internal battle.
Jocelyn is reunited with family, while Clary and the Institute's new leader disagree about rescuing Jace from Valentine, who reveals a dark secret.
Valentine comes up with a new method of winning over Jace, while Simon asks Magnus for help, and Clary struggles to balance her new and former lives.
When Alec's life is in jeopardy, Jace rushes to save his parabatai while forces in both the Shadow and Mundane worlds rise against the warriors.
Jace remains imprisoned in the City of Bones while Clary hunts a demon that penetrates the Institute, and the Clave orders a major change for Jocelyn.
After a devastating attack on the Institute leaves the Shadowhunters wounded and reeling, Clary resorts to desperate measures to reverse a tragedy.
Clary and Izzy travel to the Citadel to consult a warrior sect of female Shadowhunter weapons makers who may know more about the Soul Sword.
Luke's sister appears at the Jade Wolf, causing him to disagree with Clary over next steps, while Simon gets dating advice from an unexpected ally.
Alec plans the rune ceremony for his brother Max, but tensions running high among the Shadowhunters lead to an evening of painful revelations.
Clary must contend with the hostility of the Downworlders and the activation of Iris's blood oath, while Isabelle and Raphael become closer.
As Valentine executes his plan for the Soul-Sword, the Shadowhunters move quickly to secure the Downworld and Clary's life is placed in jeopardy.
Following Valentine's devastating attack on the Institute, the mourning Shadowhunters are forced to battle a greater demon that attacks New York City.
While Valentine and Magnus try to break out of prison, Jace struggles with a new identity, and the Shadowhunters face a possible Downworlder uprising.
The sudden deaths of several Shadowhunters forces the Institute's leadership to consider a controversial defense against a violent Downworlder revolt.
Clary, Jace and Simon depart for the Seelie Court to question the queen of the fairies, while Alec formulates a peace agreement with the Downworlders.
Simon wakes from a night out with no memory and suspected of murder, Alec transfers Valentine to Idris, and someone from Sebastian's past appears.
Given the past year's events, Simon struggles with observing the Jewish Day of Atonement, while Clary and Jace travel to Idris looking for Valentine.
As the Shadowhunters race to find the third and last of the Mortal Instruments, Clary realizes that her brother Jonathan is working for Valentine.
After an attack, the Shadowhunters are on alert and zero in on the location of Jonathan Morgenstern, who is in closer proximity than they ever knew.
After years of mistrust, the Downworlders unite to split from the Clave and hunt for the fugitives on their own, a decision that could spark a war.
The Shadowhunters battle an army of demons released by a dimensional rift, forcing them to choose between defending New York and stopping Valentine.
Clary becomes a full Shadowhunter but conceals a big secret. An owl-faced demon preys on mundanes. Magnus loses his position as High Warlock.
Jace invites Clary out to dinner but their evening ends up being a double-date. The Shadowhunters begin to realize they're under a demonic attack.
Alec hosts his mother for a family dinner with help from Magnus. Raphael faces a heartbreaking personal loss. Simon tries to enter the Seelie realm.
Jace's friends notice disturbing changes in his personality. Simon meets an ideal new roommate. Clary and Izzy pursue an out-of-control vampire.
Clary asks Cleophas for help in figuring out what's wrong with Jace. Alec learns a secret about Magnus's past. Jace is suspicious of Simon's roommate.
Magnus asks an old friend for help while investigating a demonic attack with Clary. Simon tries to make amends with a visitor who then won't leave.
Clary must confess the truth about her wish and try to find Jace before the Clave can hunt him down. Luke and Simon look for Lilith's latest victim.
Clary awaits judgment while imprisoned by the Clave. Magnus, Alec and Isabelle try to save Jace. Simon learns more about the Queen of Edom.
Clary offers the Clave something it wants in return for sparing her life, with disastrous results. Simon's past returns to haunt him and his family.
Simon makes a heartbreaking choice to protect his family. Magnus asks his father for help. The Shadowhunters prepare for a showdown with Lilith.
Luke has suspicions about Clary's fate. Izzy learns something disturbing about the Clave. Simon attempts to remove the mark from his forehead.
The Shadowhunters follow Clary and Jonathan to Paris. Life without magic is painful for Magnus. Simon continues his quest to remove the mark.
Jace is haunted by his memories of being possessed by Lilith. Clary learns about the rune that binds her to Jonathan. Luke gives Maia some advice.
Jace and Clary's date goes awry when Jonathan intrudes. Magnus makes a desperate attempt to retrieve his magic. Luke becomes a murder suspect.
The Shadowhunters seek out the vampire killers. The Twinning Rune begins to negatively affect Clary. Magnus gets a cold reception at the Institute.
Unable to remove the Twinning Rune, the Shadowhunters take another approach. His magic transfusion leaves Magnus suffering from ill effects.
Izzy and Simon embark on a dangerous mission that reveals the truth about corruption in the Clave. Clary and Jonathan recall dark childhood memories.
On Halloween night, Simon's sister keeps a tradition alive. Clary suffers when she's separated from Jace. Alec must make a big decision about Magnus.
Consumed by the Twinning Rune, Clary flees with Jonathan to a Downworlder club, where they hope to obtain Morning Star. Izzy tries to reforge Glorious.
Jonathan makes a deal with the Seelies and reveals his true form while the Shadowhunters, desperate to stop him, race into battle at Alicante.
The Shadowhunters discover a rune that will allow them to enter Edom, where they and their Downworlder allies hope to find Magnus and free him.
The allies confront Lilith at her most powerful while back on Earth, Jonathan plots a devastating attack on all the Shadowhunter Institutes.