Simon goes home to find that the glamour he put on his mom has faded. there are religious marks on the door and when he knocks on it, she tells him to go away. Clary calls him to tell him Jace and Sebastian are missing.
After two weeks of testimonies and holding the Mortal Sword, Clary waits for her verdict from the Clave in Isabelle’s room. Alec comes in to tell her that the Clave has deiced that she hasn’t broken any laws, but they are deprioritizing the search for Sebastian and Jace. Some wards have been smashed and need to be replaced. The council must continue reorganization while they waif to Sebastian to make the next move. Clary decides that she wants to talk to the Seelie Queen. Isabelle and Alec agree to go with her and they join the other Shadowhunters in the lobby. Clary tells Luke that she’s going out with her friends while Alec tells Magnus what they plan to do. Clary joins Isabelle by Aline and her girlfriend, Helen. Aline shares a story about Jace explaining why she knows Jace will find his way back to them.
Simon is outside waiting for Clary. When she comes out with Alec and Isabelle, she explains their plan. She walks with her best friend while the pair of siblings follow, talking about their dad putting his name in for the Inquisitor position. When they are far enough away from the Institute, the four of them hold hands and Clary rings the bell. they are transported to the Seelie Court. Merlion takes them to the queen, who is not impressed with their attitudes. She puts a glamour on Alec to make him appear old until Clary apologizes. Clary then asks for the queen’s help in finding Jace. She agrees if they bring her a set of fairy rings that are held in the Institute. Alec and Isabelle both agree that the theft is worth the risk to find Jace. They all leave and Alec goes to Magnus’ apartment. As Magnus tries to decipher the ritual Lilith used, Alec tries to control his jealousy over his boyfriend’s past. He goes to bed, but Magnus is still concentrating. Clary and Simon sneak into her room as he has been staying with her to help her sleep. Clary worries about her mom blaming herself for Sebastian. Simon knows Clary is doing the same thing by blaming herself for leaving Jace alone. Simon asks if she is really going to steal the rings. She plans to take them during the Conclave meeting the next day.
When Simon finally goes back to the apartment, Jordan and Maia are waiting for him. they know what happened with his mom and are worried about him. His sister has been calling and he promises that he will text her later before leaving again. Clary sneaks into the institute library. As she is about to take the rings, Sebastian and Jace show up. They act like life-long best friends and take books on demon summoning. Clary stays hidden and watches. When they have what they need, Sebastian uses a ring to teleport them out. Magnus wakes up Alec to remind him that he needs to meet the others at Turtle Pond. Alec gets upset at Magnus for not being forthcoming about his past and storms out. A hooded figure approaches Alec saying he has a message for him from Camille. Jordan asks Maia to join him in his search for Jace. She accepts, knowing she needs to figure out her feelings for him. She leaves with Simon to go to the subway. Simon and Isabelle are the first to arrive. She gets annoyed with his phone buzzing and pulls it out of his pocket. He tells her about his sister, Rebecca, and she tells him to tell her the truth. Siblings are more understanding than parents. Alec shows up and shortly after, Clary portals there.
Clary explains what she saw in the library to her friends. THey realize they have new questions, but the Seelie Queen will only answer what was originally asked. Clary didn’t get the rings anyway, so they decide not to go. They all go to Magnus’ apartment. Alec promises to talk to him that night, but has something to do himself that afternoon. Alec finds Camille in the unused town hall subway station from a letter one of her subjugates gave him. He asks her how he can become immortal as she promised when he freed her. She refuses and they fight. She finds pleasure in it and explains that there isn’t a way to make him immortal that he would agree to. However, Magnus’ immortality can be taken away. Clary starts to think of a new rune on her way home and rushes to her room to draw it. Jocelyn interrupts her and Clary asks if the protection ceremony was done to her when she was an infant. Her mom confirms that it was done by a Silent Brother and a female warlock (replacing an Iron Sister). Clary completes the rune, but doesn’t understand how it will help her. Jordan and Maia search the abandoned Navy Yard. They don’t find anything, but start talking to each other. He asks her what she wants to do for a living and offers her his savings to send her to college. He kisses her and tells her he loves her before she tells him she can’t be with him right now and leaves.
Clary wakes up from a dream to find Jace in her bed with her. He tries to explain what is going on. He wants to take Clary with him now that she didn’t tell the Clave she saw him. Sebastian interrupts them and Clary is furious that he is there. Jace convinces him to give him some alone time with Clary to explain. Jocelyn finds her son and freaks out. She pulls a knife and tries to stab him, but only cuts him. Jace starts bleeding in the same spot. Annoyed with Jocelyn calling him Jonathan, Sebastian explains his new name limits his association to his biological parents. Luke comes out with a shotgun, but as he fires, Jace tackles him to save Sebastian and himself. Luke punches him and Sebastian stabs the werewolf in the chest with a silver dagger. They disappear into thin air. Jocelyn calls the pack and tells Clary to pack a bag. They have to leave because Jace will keep coming for her.
After making sure Luke is wit his pack and stable, Jocelyn takes Clary to Magnus’. Jocelyn explains that the knife Sebastian used had something on the tip that keeps burrowing into Luke to keep him from healing. Magnus suggests the Praetor Lupus being able to help and calls Jordan. Clary tries to get her mom to agree not to kill Jace, but Jocelyn can’t. Brother Zachariah arrives, promising to keep the secret from the Clave. He explains that the two are bound and Jace is heavily influenced by Sebastian’s will. It is decided that Jocelyn will go with Isabelle to the Iron Sisters to see about a weapon that will hurt only one of the boys. Clary gets mad at Jocelyn for not letting her go. Jocelyn points out Clary and Jace’s bad luck streak as a couple, saying they are obviously not meant to be together. Clary storms off. Raphael comes to Simon asking him to be his bodyguard against Camille. Simon refuses and Raphael goes on a tirade about darkness taking over the Earth. Clary sends a text and draws a portal to get out of the apartment. Isabelle shows up at Jordan’s apartment looking for Simon. He gives her tequila while she explains that she really likes Simon and hasn’t felt that way about anyone before. He convinces her to tell him how she feels. She starts getting ready to go to Clary’s to do it before she looses her nerve, but passes out instead.
Clary meets Simon at Taki’s to tell him her latest plan. She has the fairy rings the queen wanted. She plans to go with Jace and Sebastian and use the rings to tell Simon where they are. Simon protests, but she points out that she is going to do it with or without his help. Maia shows up at Jordan’s to tell him about Luke needing the Praetor’s help. Isabelle comes along and tries to explain that she was waiting on Simon. Maia tells her to go to Magnus’ right away. Jordan agrees to take Maia to headquarters to request help. Isabelle arrives at Magnus’ and he tells her that they need her to go to the Iron Sisters with Jocelyn. He also wanted her there to comfort Alec. Clary goes to Luke’s house to wait for Jace. She and Simon test out the rings at a distance and can still talk. Simon goes home to find a note from Isabelle asking him to come to Magnus’. He leaves right away. Magnus directs Simon to the room Isabelle is staying in and he goes back to find her sleeping. He crawls into bed with her and she wakes up, surprised that he came. Jace eventually arrives for Clary. he tells her that if she goes with him, she won’t be able to come back for a long time. She agrees.
On the way to the Praetor headquarters, Jordan stops to watch the sun rise. Maia tells him she wants to go slow and just be friends before anything else. He explains that he loves her and cannot be just friends. She kisses him. Clary wakes up and starts exploring where she is. She finds Jace’s room and then Sebastian’s. As she backs out of her brother’s room, he finds her and asks what she was doing in there. Magnus and Alec take Isabelle and Jocelyn as far as they can before they go off on their own to confront the Iron Sisters. Jace arrives and Clary acts like nothing happened. They sit down at the table to eat and Sebastian explains that the moving apartment was Valentines. He decides to wait a week to tell Clary their plan. Isabelle and Jocelyn arrive in a plain and start walking. Isabelle asks Jocelyn about her parents’ relationship, but Jocelyn doesn’t think it is her place to tell. They arrive at the draw bridge to the Adamant Citadel. Isabelle cuts her hand to offer blood while starting their motto.
Alec sneaks off to meet with Camille. She tells him that she will do the spell to make Magnus mortal if Alec kills Raphael. Isabelle and Jocelyn cross the bridge with random knives and swords through it to explain the situation to two sisters, Chloephas and Debres. They cannot help and say they need a weapon of great power, such as the angel Michael’s sword. However, they don’t really have any way to summon an angel. Isabelle is furious and frustrated. She storms off. When Jocelyn gets to her, she tells Isabelle that the sisters think she would be great as one of them. Jordan and Maia arrive at the Praetor House and explain the situation to Praetor Scott (Woolsey’s descendant). He agrees to look at their books to help Luke and reminds Maia of the promise she made in her pack leader’s name to have the ear of a council member. Simon wakes up and joins the others. They are talking about summoning an angel, which they determine to be unrealistic. Magnus suggests they summon the demon Azazel for a weapon since his physical form can’t come into their world. Jocelyn wants to get Clary out of there before they summon any demons. Simon tells her Clary is gone.
Jordan takes Maia to his dorm-like room. his roommate is on assignment so he tells her to get some rest. He goes to shower and Maia joins him after the realization that more fighting and death is on the way. Simon explains Clary’s plan and Jocelyn is furious. Isabelle points out the mistakes Jocelyn has made with Clary and sticks up for Simon. Jocelyn leaves. Jace shows Clary around Venice. he asks her about the fairy ring and she tells him she got it from Isabelle. She also tells him that Magnus has the Morganstern ring to try to find him. He promises to show her the world. Maia and Jordan are wrapped up in each other when someone knocks on the door to tell him Praetor Scott wants to see him. Back at the warlock’s apartment, Simon, Magnus, Alec, and Isabelle get ready to summon Azazel. Praetor Scott gives Maia a salve for Luke that should draw out the demon metal. Raphael projects himself into the room to complain about Maureen running wild. Jordan’t roommate, Nick, is assigned to her and Raphael sin’t happy that she is making his clan look bad. Jace and Clary borrow a boat and lay in it. As they kiss, she tries to remember that it isn’t her Jace she is with. He shows her the Wild Hunt - Faeries that rid across the sky and once a year allow a mortal to join them. The man whose boat they stole stars yelling at them.
Magnus, Alec, Isabelle, and Simon summon Azazel. He agrees to tell them a way he can help, but they each have to give him a happy memory. they all agree and Magnus gives them to the prince of hell. He tells them that short of angel fire, they don’t have much hope of severing the bond between Jace and Sebastian. He tells them that if they set him free, he will take Sebastian to hell with him. After a while, the bond would be burned away. Magnus banishes the greater demon so they can discuss their options. Maia and Jordan arrive to tell them Luke will be fine. Jace and Clary arrive back at the house. Sebastian is there with two girls, one of which is a vampire. Jace declines his offer to join them and takes Clary to his room. He holds her and they sleep. Isabelle asks Simon to stay at Magnus’ with her. He agrees knowing he will need blood soon. Alec goes to see Camille and tells her that he cannot kill Raphael for her. He starts asking her fro relationship advice, knowing she was once involved with his boyfriend. Clary wakes up from a bad dream and quietly leaves Jace’s room. There is blood in the hallway and Sebastian comes out of his room. He assures her that the human girl is safe and they make their way to the kitchen. Sebastian tries to convince Clary that killing Max was an accident and the bond with Jace has changed him. She agrees to hear his plan before deciding what to think of him, but has trouble hiding her hatred for him.
Alec sneaks back into bed hoping that Magnus won’t realize he was gone. He doesn’t account for the cat being under the covers and wakes him up. Magnus knows he’s been out, but Alec refuses to say where. Simon and Isabelle lie together awkwardly until they start fooling around. Isabelle realizes that Simon needs to feed and offers her blood. After a while, he can’t resist and bites her. She enjoys it and they sleep comfortably. Clary wakes up and checks the hall, but the blood is gone. When Sebastian comes out of his room, Clary decides to change. She meets Sebastian and Jace in the kitchen. THey tell her they have an errand to run when Clary notices the house moved from Italy to Prague. Sebastian agrees to let her join him if she draws a strength rune on him. She does and finds scars Valentine cut into his back with demon metal. Maryse calls the Silent Brothers and Brother Zachariah arrives. She shows him a map that she uses along with Valentin’s rune on Jace to know where he is. Brother Zachariah agrees to not say anything yet, but warns her that if Jace stays anywhere long enough, she will have to inform the Clave. Clary sneaks away for a few minutes to exchange progress with Simon. She continues on with Sebastian and Jace to a store filled with junk and run by a dragon-like demon named Mirek. Sebastian offers Mirek their agreed upon price for a block of adamas (what is used to make seraph blades). The demon refuses because Sebastian didn’t come alone. He asks for a lock of Clary’s hair. Jace and Sebastian refuse. Sebastian continues to refuse to pay more than the agreed price and pulls out his seraph blade. The next thing Clary knows is the snake-like demon is over her. Simon and Isabelle wake up. They start getting close when Magnus knocks on the door to tell them he has news.
Elapid demons start appearing everywhere. Sebastian, Jace, and Clary fight them off. Sebastian yells for Clary to stop Mirek from running away with the adamas. She kills him-and grabs the rock. Sebastian takes it from her and Jace makes sure Clary is alright. The pentagram used to summon Azazel allows him to communicate with the group. Magnus brings him back to tell him they re going to decline his offer. Azazel decides that he doesn’t like that answer and will try to find his own way out of the pentagram. Chairman Meow (Magnus’ cat) runs into the pentagram and Simon dives in to save him. Azazel sees his opportunity and attacks. The mark of Cain drives him back. He leaves saying he doesn’t want any association with anyone that would use that mark. Jace and Clary give each other healing runes and get ready for the next step in Sebastian’s plan. They are going to a club. Simon talks to Magnus about summoning an angel. The warlock can’t guarantee that the mark will keep him safe, but agrees that Simon is their best option. Sebastian leads Jace and Clary to a lower level of a club where werewolves and vampires are dancing. He leaves the couple behind to go talk to someone. As everyone argues over whether or not Simon should attempt to summon Raziel, he and Isabelle talk. She isn’t happy it has to be Simon, but lets him make his own choice. Jace convinces Clary to try the silver Fairy liquid falling from the ceiling. She is instantly high and dances away from Jace and into Sebastian. He tries to explain their similarities to her, that they both have some darkness. Jace comes along and takes her back to the dance floor, but they are mostly just kissing. They move t a curtained alcove to be alone. Sebastian meets with Merlion to talk about ending the human race. The Seelie Queen sides with Sebastian. While making out with Jace, the silvery liquid seems to turn to blood. All of the clubs decorations seem to be corpses. Clary freaks out and then faints.
Clary wakes up in Jace’s room. He tells her the gory images she saw weren’t real before he falls asleep again. She realizes her ring is missing and goes to look for it. Sebastian is leaving the house and she decides to follow him. Luke wakes up and agrees to Jocelyn’s request to take it easy. With Clary gone, she needs him. They talk about their past and Clary’s willingness to die for what she believes in. Clary follows Sebastian to a building, but looses him and ends up in a courtyard. She keeps searching and overhears demons talking about killing Jace after Sebastian’s plans are successful. Clary runs, but they follow. She tires to fight them off with an ornamental axe, but is poisoned. Sebastian saves her and starts carrying her away.
Clary wakes up on a park bench wondering why Sebastian saved her. He points out that she is his only family. He knew she was following him and wanted to see what she would do. She asks about the demons. He points out that more and more are spilling into the world. He is trying to understand them and gain their trust to help Shadowhunters in the upcoming war. Clary can’t believe him, so he wants to prove that he has a plan. While everyone works hard researching how to summon Raziel, Simon gets a text from Maia updating him on Luke’s status. Since they will need a large space, he suggests Luke’s farm. Magnus agrees and suggests they get some sleep first. Sebastian tells Clary what he knows about their family and speculates what it would be like now if they had grown up together. He takes Clary with him to Magdalena, an outcasted Iron Sister who supported the Circle. He gives her the adamas. She promises to make what h asked for and they leave.
Sebastian takes Clary home and to the secret training room. Jace is there and upset that he didn’t know where Clary was. Sebastian explains that he took her to meet Magdalena. He wants her to use the adamas to make a second mortal cup. He explains that they will lure out the greater demons by telling them they want to mix blood to start a new Shadowhunter race. Clary is a bit overwhelmed by the information and says she needs to sleep. Jace goes with her. Simon meets his sister, Rebecca, in person. She thinks their mom has gone crazy and needs to be committed. Simon tells her the truth. Rebecca is quick to believe and trust him, saying they’ll figure it out. Jace and Clary start making out in his room, but she quickly puts a stop to it when Jace starts undressing her. She is a little spooked from the previous night with the fairy drugs. Jace storms off. Jordan is restless while Maia is off talking to Luke about what is going on. When she returns, they immediately start hooking up again. Jace comes back in his room to apologize to Clary. he tells her he is happy to be with her and will wait until she is ready. She asks him to read to her to help her sleep. He picks up the copy of A Tale of Two Cities that Will gave to Tessa.
Magnus, Alec, Isabelle, and Simon make their way to Luke’s farm in Jordan’s truck. Alec talks about the little things that make being gay difficult. Clary wakes up in her room to the sound of Jace and Sebastian talking about Jace retrieving the cup. Jace comes in and Clary instantly knows it is the real Jace. he goes to his own room and she sneaks after him. He explains that Sebastian sent him to retrieve the cup and kill Magdalena. He doesn’t think that Sebastian knows that the Iron Sister cut his mark of Lilith with a blade made with angel blood. He tells her that Sebastian really wants to start a race of dark Shadowhunters. He wants to move the house near an entrance of the Silent City so he can turn himself in and sacrifice himself to stop Sebastian.
Simon tires to contact Clary with no luck. Isabelle is worried, but Simon is oddly calm at first. Magnus calls him over and gives him what he needs to complete the spell. he says his last words to his friends before he starts chanting. Clary refuses to let Jace go through with his suicidal plan. She calls for Sebastian. He puts an iratze on Jace’s chest to heal the rune. Jace tells Clary that the other him came up with the plan. he’d rather be dead than be that person. Sebastian is willing to trust Clary now. Raziel appears to Simon and is not happy to be summoned. The angel sees the Mark of Cain. He agrees to help Simon if he is willing to give it up. Simon agrees. Raziel gives him Gabriel’s sword, Glorious.
Clary Frantically searches Jace’s room for a stele. Sebastian gives her a red dress and tells her she has an hour until the ceremony. Clary says she is going to get ready, but instead, she sneaks into Sebastian’s room and finds her fairy ring. Simon hears Clary in his head. They fill each other in on what has been going on. Clary breaks off and Simon fill in the others. Sebastian catches Clary in his room with the ring. He explains that the Seelie Queen has been listening in on her conversations and he uses it to communicate with her. Clary smashes the ring before he can learn about the sword. She punches him, grabs his stele and runs. Knowing they will need reinforcements, Magnus splits up the group to get help. They get ready to portal, but first Isabelle grabs the sword and gives it to Simon. Clary runs to the kitchen where Jace told her the house is controlled and draws a rune. Sebastian catches up to her and they start fighting. It doesn’t take long before he has her pinned to the ground. He tells her that they belong together and seems to be jealous of Jace. Clary starts stabbing and slashing him with glass shards.
Clary can’t kill him and he knows it. She gives up and he tells her to get cleaned up and ready for the ceremony or she will not like what he does to her. Jordan gets a call from the Praetor. His roommate, Nick, was killed, most likely by Maureen. Maia then gets a 911 call from Luke calling the pack to battle. Sebastian retrieves Clary from the bathroom, now dressed in her mom’s ceremony dress. He walks behind her with a crossbow as they leave the house. Isabelle and Alec arrive at the Institute and find Maryse talking to Aline and her girlfriend, Helen. They tell them everything and Maryse says she has to tell the Clave or they could loose everything. The siblings decide they will have to do it on their own. Sebastian takes Clary out of the house and then it is destroyed by the rune she created. He takes her to the tomb where everyone is gathered on a plain. Jace speaks to them about taking over the world. He lets Sebastian take over, who calls Lilith. They mix blood in the Infernal cup and Cartwright brings Amatis up to drink first.
Sebastian and Cartwright force Amatis to drink from the cup. She is instantly different and Sebastian has her demonstrate her new power. They other Shadowhunters are ready to drink. As they turn their alliance to demonic, Clary’s family and friends arrive. They know they need to get Simon to Sebastian. Isabelle and Magnus move with him. AMatis attacks and stabs Magnus, who falls. Simon tires to help, but is carried forward by the battle. Jace holds Clary back while she tries to free herself to join the fight. Sebastian tries to get her to drink from the cup while Jace argues that it is too soon. She gets free and runs into battle. Maia and Joran fight together as a team. Simon makes his way toward Clary through a path Alec clears for him. Jace is chasing Clary, but she gets to Simon first. He gives her the sword. While Jocelyn looks for Clary, a younger Circle member approaches her, explaining that they are no longer Nephilum. Maryse kills him and goes back to the battle. Jace blocks Clary’s way to Sebastian knowing it isn’t her Jace, she stabs him in the chest and he erupts into flames. Alec rushes down to Magnus and lends the warlock his strength to heal himself. Jace crumples to the ground and Clary crawls to him. Her mom and Simon try to get her away from Jace’s body, but she waits for a sign that he is still alive. His hear is beating.
Isabelle gives Clary the idea of going to see Jace even though the Silent Brothers keep saying no visitors. Alec goes to see Camille, but finds Magnus instead. Camille told the warlock about her deal with Alec. Magnus breaks up with him. Alec challenges Camille, but Maureen appears, explaining that she killed Camille and now leads the New York clan. Clary convinces Brother Zachariah to let her see Jace. She apologizes to Jace and he tells her everything he remembers. He also tells her that Gabriel's’ sword left heavenly fire in him. The Silent Brothers are going to help him control it, but in the meantime, touch will be difficult. Maryse shows the Silent Brothers the angel wings Sebastian left on the Library floor.