Jonathan begins his reign of vengeful terror as the Shadowhunters try to find a way to stop him. With only one hope, Clary must make a sacrifice that could have long-lasting implications for all. Meanwhile, wedding bells are in the air for one special couple.

In the climactic mid-season finale, the team scrambles to find a way to put a stop to Lilith’s plan coming to fruition. But going up against their biggest opponent yet, their odds are not looking good. Meanwhile, Simon makes a heartbreaking choice with Isabelle’s help and Magnus reconnects with a powerful person from his past.

Clary comes up with a plan that will bring Shadowhunters and Downworlders together, as Alec struggles for a way to help Magnus.

Alec, Jace and Isabelle make a plan to finally get Clary back and stop Jonathan—much to Luke’s and Simon’s chagrin. Meanwhile, an emotionally raw Magnus struggles to deal with his father’s reappearance and Maia must make a tough decision that could affect the rest of her life.

Jace and Clary rush to make a final stand, but when a traitor is revealed, Jace and Clary may have a bigger fight on their hands than expected. Meanwhile, Alec and Izzy must fight off a large mass of demons that have unexpectedly shown up, as Luke and Simon head to the Seelie Court to deal with some unfinished business with the Seelie Queen.

The New York Institute is under attack as Valentine’s plan for The Soul Sword is getting dangerously close to coming to fruition. The Shadowhunters must act fast to save their loved ones and the rest of the Downworld. Meanwhile, some of the Downworlders have their own plan to stop Valentine and their target is Clary.

Clary faces down an old foe in an attempt to find answers about Lilith’s plan. Alec and Magnus turn to Lorenzo Rey for help, while Lilith finds a new ally. Luke must choose between his pack and his family, as Simon is forced to deal with his past.

Clary teams up with Magnus to investigate a recent demon attack. Simon is stunned with he’s visited by someone he never thought he’d see again, and who now won’t seem to leave. Meanwhile, Izzy worries about dinner with her family and a special guest and Luke reaches out to Maryse.

With the Owl's identity revealed, Alec, Isabelle, and Clary head to Alicante to try and find a way to stop him. Luke and Simon team up to track Lilith's latest possible victim. Maia reflects on her past.

After a devastating attack at The Institute, everyone is on high alert as the Shadowhunters close in on their hunt for Jonathan; Simon and Maia help a new Downworlder as the Seelie Queen demands an answer from Magnus and Luke.

The Warlocks’ magic is becoming corrupted by a demonic presence while Izzy and Luke try to track down more information on the recent series of possessions.

With the loss of Clary after Lilith’s apartment exploded, Alec, Isabelle and Jace try to come to terms with what has happened. Glad to have their brother back, Alec and Isabelle are still worried about Jace, who is taking the actions of The Owl very hard. Magnus is also mourning the loss of his magic and finds himself in a new position—having to rely on others for help. Meanwhile, Maia tries to help a devastated Simon who has lost his family and his best friend. But unknown to everyone, Clary is alive and finds herself in a new and dangerous predicament.

Magnus, Alec and Isabelle try to reach Jace inside The Owl, but even as powerful as Magnus is, can he help the Lightwoods retrieve their brother from his demon prison? Maia and Jordan join Simon on the hunt for Lilith, while Luke tries to find a way to get to Clary.

Someone is out to get Simon and Jace is on the hunt to find out who it is, meanwhile Clary turns to Luke to find a way to help Jace. Alec worries about the future of his relationship after learning more about Magnus’ romantic past.

A demon outbreak in New York City on Halloween becomes a top priority at the Institute, but as the Shadowhunters hunt the demons, Jace becomes more worried about Clary. Meanwhile, Alec has to juggle the outbreak with his deep concern about Magnus’ depression.

After several Shadowhunters are killed, The Institute turns to controversial methods to prevent a Downworlder uprising.

Luke’s sister shows up at the Jade Wolf claiming innocence about the recent attack. But with Luke not trusting a word Cleo says, he finds himself at odds with Clary who sees an opportunity to get to Valentine. Yet how far will Clary go to prove she is right about Cleo? Meanwhile, Simon gets dating advice from a surprising source as Isabelle takes a dangerous path.

With Simon being held captive at The Hotel DuMort, Clary pleads with Jace, Alec and Isabelle to help her rescue her best friend. As the team readies for the mission, Jace helps Clary learn more about her Shadowhunter powers, Isabelle turns to her favorite Seelie for Intel, and Alec begins to question Jace's motives and his place in their partnership. Meanwhile, a very scared Simon gets very up close and personal with Camille, the leader of the vampire clan.

With the knowledge that Valentine is alive and on the hunt for The Mortal Cup, the Institute is on high alert. Not wasting any time, Jace jumps into action and figures Clary’s memories are the key to finding Jocelyn and The Mortal Cup. Unfortunately, Clary’s memories were wiped leaving her without any recollection of this other life that could help her and the team. With only one other option remaining, Jace, Isabelle and a very reluctant Alec take Clary to the City of Bones to face the powerful Silent Brothers. Meanwhile, Luke continues his search for Clary, and Simon tries to come to terms with his best friend’s new life.

One young woman realizes how dark the city can really be when she learns the truth about her past.

Only hours have passed since Jace left with Valentine and all hell has broken loose at The Institute. Alec, Isabelle and Clary are desperate to find Jace, but are quickly stopped in their tracks with the arrival of Victor Aldertree, who means business about getting the Institute back on track. But getting the New York Shadowhunters in-line with The Clave may be counterintuitive to Alec, Isabelle and Clary's plan to rescue Jace. Meanwhile, Jocelyn has a lot to catch up on now that she is awake.

After getting a clue about who may have wiped Clary's memories, the crew hunts down the High Warlock of Brooklyn, Magnus Bane. With all of the warlocks in hiding from Valentine, the team must lure Magnus out with something he can't refuse - a killer party and something very valuable. But with emotions running high, more may come out of their meeting with Magnus than just the retrieval of Clary's memories. Meanwhile, Simon doesn't seem to be himself after his recent Downworlder encounter.

Tensions escalate between Alec and Clary as they don't see eye to eye on the best way to hunt down Valentine. But when Jace and Isabelle are sent on an intel mission to the Seelies by Maryse Lightwood, Alec is put in charge of keeping Clary safe, much to both of their chagrin. With his hard-as-nails mother back in town and Clary's rule-breaking tendencies, Alec finds himself struggling to stick to the Claves rules while keeping his promise to Jace. Meanwhile, the New York City Werewolf pack begins their hunt for Clary and The Mortal Cup.

With word of Alec, Jace and Isabelle’s “extracurricular activities” with Clary reaching The Clave, a convoy is sent to observe the Lightwoods running the New York Institute. Once The Clave representative arrives, it is very clear how much trouble the Lightwoods are in. Meanwhile, Clary is faced with a devastating decision.

With Luke in dire need of help, Jace, Clary and Simon take him to Magnus' lair in hopes of saving his life. Once there, the story of how Valentine came to be evil, and Jocelyn and Luke's past is revealed to Clary in hopes of triggering her memory of what happened to The Mortal Cup. Meanwhile, Isabelle and Alec are tasked to restore their family name in the eyes of The Clave.

After the attack, the Institute and The Clave are on high alert and taking no prisoners to get answers. When Lydia makes a harsh call on the Seelies, Jace, Clary and Isabelle fear that this decision could be disastrous and the wrong way to defeat Valentine. Left with no other choice, the trio takes drastic actions to stop what is about to take place. Meanwhile, Simon struggles to deal with his new situation, and Alec is emotionally torn with what is happening at the Institute.

The hunt is on for Jace Wayland, and Alec and Isabelle hope to reach him before the rest of the Shadowhunters do. With orders from the Clave of “shoot to kill,” the Lightwood siblings must act fast. Also on his own search, Simon turns to Magnus for help when he finds himself at odds with both Raphael and Aldertree. Meanwhile, Clary struggles to find where she belongs since she doesn’t seem to fit into the Shadowhunter world, yet can’t go back to her mundane life.

After receiving important intel about Valentine from a surprising ally, Clary, Jace and Luke devise a plan to rescue Jocelyn. With the mission looking almost impossible, the three will stop at nothing to rescue Clary’s mother and put a stop to Valentine once and for all. Meanwhile, Inquisitor Herondale arrives at the Institute for Isabelle’s trial as Alec turns to Magnus for help.

Jace, who is still reeling from everything that has happened, makes hunting down Valentine his number one priority even though he continues to wrestle with his conflicted feelings. In hopes of finding a way to stop Valentine before it is too late, Clary and Simon must find the key to unlocking Jocelyn's coma. But that key to unlocking Jocelyn’s spell may just undo the Downworlder peace treaty, Simon's relationship with Raphael, and the Vampire clan in the process. Meanwhile, Alec must deal with the aftermath of his decision and what his choice means for his future.

After piecing together the clues as to where her mother hid the Mortal Cup, Clary, Jace, Alec and Isabelle are on the clock to find its hiding place before anyone else. But with demons and Downworlders lurking everywhere, obtaining the Cup may not be as easy as they had hoped. Meanwhile, as Simon's symptoms become increasingly worse, he fears he is turning into a vampire.

Clary and Jace get a tip from Meliorn that they can find Valentine by locating a portal in another dimension, but only Clary can venture into this new world. What Clary finds in this alternative universe is that life there is as if the threat of demons no longer existed and Shadowhunters were no longer needed. While she realizes that this dimension is the life she always dreamed of, Clary must act fast or she will lose herself in the alternative world forever. Meanwhile, Alec and Isabelle must face the consequences of the Downworlder attack.

After the recent attack on the Institute, the Shadowhunters are left devastated and wounded. Trying to regroup, each of the Shadowhunters deals with the situation their own way. Meanwhile, Simon moves home but finds it is not so easy to pull off his new life with his family around.

Already cut off from the Institute and his friends, Jace finds his situation worsen when he becomes a target for the New York wolf pack who believe Jace to be a killer. And don’t forget about Aldertree and the Shadowhunters who continue their own hunt for Jace! With Jace becoming the most wanted man in New York, can his friends get to him before everyone else? Meanwhile, Simon is on a search of his own as Raphael puts pressure on him to find Camille.

With word getting out that Clary is a key part of Valentine’s plan, the Downworlders are at odds on how to handle the issue. But when Iris activates her blood oath, Clary has more to worry about than hiding from Valentine and the Downworlders. Meanwhile, Isabelle and Raphael get closer as Alec tries to figure out what’s going on with his sister.