The Shadowhunters' Wiki
The Shadowhunters' Wiki
SPOILER WARNING: Plot details follow. Caution is advised!
For details about his other identity, go to the respective page.

Whatever you are physically, male or female, strong or weak, ill or healthy—all those things matter less than what your heart contains. If you have the soul of a warrior, you are a warrior. Whatever the color, the shape, the design of the shade that conceals it, the flame inside the lamp remains the same. You are that flame.

–Jem to Tessa, Clockwork Angel

James "Jem" Carstairs is an inactive Shadowhunter and a former Silent Brother. Once an orphan living in the London Institute during the 1870s, along with his parabatai, Will Herondale, he is now a mortal who is over a hundred years old, cured of his illness.


Early life[]

Jem was born in Shanghai, China, to his British father, Jonah Carstairs, and Chinese mother, Ke Wen Yu. He was raised at the Shanghai Institute, run by his parents. He lived there until he was twelve, when the Greater Demon Yanluo, in retaliation for the destruction of his nest, killed his parents and tortured him by poisoning him with yin fen—a demon poison which can be made into an addictive drug. Jem was in and out of consciousness and had become delirious, and by the time the Shanghai Enclave came to investigate, his parents were dead and he was already addicted to the drug.

Jem was rescued, though his dependence on the drug could not be cured. While Jem needed the drug for continued survival, regular doses of it were also deadly, so it became known since then that Jem would not live long.

Soon after, Jem was brought to the London Institute, where he was cared for and doted on by Charlotte Fairchild. There, Jem also met Charlotte's husband, then fiancé Henry Branwell, the Sighted mundane servants Sophie Collins, Thomas Tanner, and Agatha, and the wards of the Institute, Will Herondale and Jessamine Lovelace.

CJ Young Will & Jem 01

Will and Jem meet for the first time.

When Jem arrived at the Institute, Will was also fairly new, having arrived half a year before him. The day he arrived, Will did not greet him with the others, so Jem was instead brought to the training room by Charlotte to meet him. When Will, in an attempt to dissuade Jem from befriending him, teased him about looking weak and close to death, Jem told him about his short lifeline. Jem then told him not to pity him and instead allow him to train with him and Will agreed.

Jem was the only one in the Institute to ever get through Will, who thought the curse he had on him would not matter with Jem as he was already dying. Almost a year after they met, Will asked Jem to become his parabatai. Jem initially refused, thinking Will deserved someone who would be able to look after him for a long time. However, the insistent Will wagered that if he could successfully get Jem's sword away from him, they would be blood brothers. Jem agreed and lost the bet. A year later, when they were both fourteen, they underwent the parabatai ceremony and have been inseparable since.

When he was fifteen, the demon Yanluo was finally slain. His uncle, Elias, invited Jem to move to Idris with him, though he refused so he could remain with Will. Around this time, Jem had also asked Will to promise him to stop looking for a cure for him.

Tessa and Mortmain[]

Jem was seventeen when he first met Tessa Gray. He and Will were investigating the death of the mundane Emma Bayliss, which led them to the Dark Sisters, though Jem was not part of the raid on their house since he was too ill. Instead, he met Tessa the evening after Tessa's rescue, when she came into his room while he was playing the violin. He first mistook her for Will but didn't mind finding her at all. The two talked for a while, mainly about losing their parents, before a drunken Will arrived and Jem burst into a fit of coughing.

The following day, Jem and Will were sent to the Dark House to further inspect it. There, they found the body of the Dark Sisters' clockwork servant, Miranda, which seemingly woke under Jem's touch. The creature warned them of some unknown danger before shutting off again. They brought the clockwork girl back to the Institute to be studied by Henry.

Over the next few days, Jem worked closely with Will and Tessa on their investigations. He was particularly good to Tessa, mostly to make up for Will's misbehavior. Jem tried to help Tessa understand Will and adjust to London. He also guided Tessa while she learned of the Shadow World, telling her of vampires, after she met Camille Belcourt and had to Change into her. He also tried to help her understand her own warlock power.

When Tessa ran off into the London Institute after being upset by Will, Jem found her and took her for a walk. He took her to a bridge that wasn't visited that often because it didn't have a great view. He told her that this was his favorite place to visit when he needed to get away. They were suddenly attacked by two clockwork people, one of them being the Dark Sisters' coachman. Jem fought them off, but became ill and started coughing when suddenly they were attacked by a whole army of the clockwork people. He and Tessa made it back to the Institute. By the time they got there, Jem was extremely ill and couldn't respond to Tessa. Tessa couldn't open the Institute doors because she was not a Shadowhunter. Will and the other Shadowhunters came out just in time and defeated the clockwork army, some of them escaping. However, Jem was injured and was taken back into the Institute.

Jem was treated and had to rest in bed. He wanted to speak to Tessa however and asked Will to call for her. He told her not to blame herself and then explained that he is addicted to yin fen, a drug that makes him severely ill when he suffers through withdrawal.

Jem showed Tessa the silver powder, yin fen, that satisfied his body's need for demon blood. Will bought the drugs for Jem because Jem didn't want to buy them himself, guilty of the fact that he needed the drugs in the first place. Without the drug, his natural Shadowhunter powers were weakened until he took more of the drug. Jem also had said that he took as little of the drug that he could as possible. Tessa noticed that after taking the drug, Jem's face seemed to have a slight flush to it and his eyes seemed brighter and that the powder had a sweet smell to it. She accidentally knocked the box where Jem kept the drug over while she and Jem were kissing passionately. It was presumed that Jem snorted or sniffed the drug as opposed to smoking it as Will said that the smell of burning yin fen that a pack of werewolves were taking as sweet-sour scent to it as opposed to just the regular sweet smell. Jem witnessed the werewolves dying from taking too much of the drug, and simply stood back and watched frightened. It was unknown how long the drug would take to take its final effect on Jem.

While the Shadowhunters were attacking Alexei de Quincey's clan, Axel Mortmain visited the Institute. Will and Jem went out to hear what he had to say. He told them the location of the remaining Dark Sister, Mrs. Dark, who was supposedly going to help the Magister raise his clockwork army. The two of them left immediately, although Jem was unsure whether it was the right thing to do.

When they arrived they were attacked by the Dark Sister. She used her powers to set the building around them on fire, but they managed to kill her. Jem grabbed a cat that had been locked up in a cage. Once they had escaped they realized that it must have been all a trap and that Tessa and the group were in trouble. Will rode on ahead of Jem and began attacking the clockwork army. Jem arrived a little later and helped Will until the rest of the Shadowhunters arrived.

At the end of the book, Jem had revealed to have named the cat Church. Jem also comforted Tessa when she believed that because she was a warlock, she could not have children.[3]

Running out of time[]

Jem, Will, and Tessa visited the York Institute to find out more about Mortmain's history and why he was so determined to kill Shadowhunters. Jem gave Tessa the Carstairs family ring as an engagement ring so she can pretend that she was a mundane who was preparing to Ascend and become a Shadowhunter. They met Aloysius Starkweather who showed them his spoils of war from killing Downworlders, making Tessa faint after seeing heads and body pieces of warlocks.

Jem proposed to Tessa, she accepted and he gave her his jade necklace as an engagement present. Sophie Collins was happy for them, because although she previously had liked Jem, she wanted him to be happy.[4]

Silent Brotherhood[]

It was revealed after a fight that Jem had been taking twice as much of the drug to make Tessa believe that he was getting better. Jem fell extremely ill, and there was no more yin fen for him, due to Mortmain stealing it all; Mortmain blackmailed Tessa into doing her binding until she did what he wanted: transformed in John Thadeus Shade.

Later, after Will went out to find Tessa, Jem fell more ill and told everyone that it was over, meaning that they should stop searching for a cure. It was thought that Jem died because Will's parabatai rune was bleeding and he felt their connection die.

It was revealed that he became a Silent Brother at the end of the book, and he was in fact Brother Zachariah. And as Brother Zachariah, he met Tessa once a year in the Blackfriars Bridge.[5]

For further information about his life after this, go to Brother Zachariah's page.

Finding a cure[]

At last, 129 years after he was made into a Silent Brother, Jem was "cured" from his state, when the yin fen in him was burned away by the heavenly fire in Jace Herondale, whom he constantly looked after for being Will's descendant. Upon recovering, Jem was once again a mortal. The repressed emotions that did not bother him as a Silent Brother came flooding back, and he found himself unable to reclaim his Shadowhunter name and stead. Despite this, he chose to fulfill his duties and fight alongside the Nephilim in the Dark War. Though he was more than tempted to immediately go to Tessa and tell her everything, he chose to keep her away from the danger of the war.[6]

Only days after the war, Jem quickly decided that he would no longer be an active Shadowhunter, unable to bear the thought of being one without his parabatai. At their annual meeting at the Blackfriars Bridge, Jem reunited with Tessa, and the pair shared a kiss and agreed to explore the world together. They rekindled their relationship, and, eventually, their engagement.[6][5] The same day, the couple went to Tessa's flat in London, where Jem soon lost his virginity.[7]

Eventually, Jem began playing the violin again, though his skill was no longer what it was before he became a Silent Brother. He settled with it, as he simply hoped to find in music a way to process and express his losses and new discoveries.[8] Also, after his transformation, several regulars of the Shadow Market sent him an embroidered cloak with a note that said, "You'll always be our favorite Silent Brother."[9]

In May 2008, he and Tessa attended Jocelyn and Luke's wedding in New York. There, Jem also reunited with Church, whom he took, without express permission from the Lightwoods, with him and Tessa. Even during the war, Jem had already known that he wanted to look out for the young and newly-orphaned Emma Carstairs. With Tessa, he moved to Los Angeles to be able to keep an eye on Emma and the Blackthorns, a branch of Tessa's descendants.[6]

He also later attended Emma's parabatai ceremony with Julian Blackthorn. There, he finally told Emma about him being a Carstairs.[10][11]

In 2010, Shinyun Jung went after Tessa with a Svefnthorn. Tessa sought refuge in the Spiral Labyrinth to keep herself safe and to research. Jem on the other hand, went to Shanghai, expecting Magnus and his friends to be headed there soon. He was right and was in fact able to help Magnus who was suffering from a wound of the thorn himself. He offered them further assistance in their journey but Magnus declined, knowing Tessa would be mad if anything happened to Jem under his watch. Jem also told Magnus that he and Tessa had gotten married in a mundane ceremony at a courthouse—believing that a real ceremony would put their loved ones in danger. Magnus swore that after this whole business was resolved, he would help them find a way to truly celebrate their marriage while keeping everyone safe.[12]

Two weeks later, Magnus used oneiromancy to throw them a dream wedding. Everyone besides the couple, Magnus, and Alec would believe it to have just been a dream and slowly forget, but for Jem and Tessa, they'd know their souls were there to celebrate with them. They chose Blackfriars Bridge in London as the location, and Magnus officiated. They exchanged rings engraved with Mizpah. Before the dream ended, Will's soul supposedly made an appearance to congratulate them.[13]

The Lost Herondale[]

During his time in the Silent Brotherhood, Jem learned of a lost line of Herondales and began searching for them. After he returned to the mortal world, Jem continued his search for Tobias Herondale's descendants with Tessa by his side.

In 2012 their quest led them to the Buenos Aires Shadow Market, where there were rumors of someone telling stories of the Herondales. However, when they arrived and attempted to enter, they were denied and told the only Shadowhunter welcomed there was Alec Lightwood. They called on him for assistance and upon entry were requested by the Queen of the Shadow Market to look into the disappearances of several werewolf women. They agreed and were able to track down the culprits and arrest them, saving the women who were still alive and repairing the relationship between the Market and the Institute.

While they were asking questions around the market, Lily Chen recognized one of the vendors as someone who had a long grudge with the Herondales. Thanks to this tip, Jem and Tessa were able to find that the source of the rumors was Mother Hawthorn. She reluctantly told them the story of the First Heir's line. Now, with the knowledge of the exact threat posed to Rosemary Herondale, they set themselves back on their search to find and protect her.[14]

Several months later, Rosemary used the heron necklace he had given her to summon him for aid. Unfortunately, Tessa and Jem arrived too late to save her; with her dying breath, she was able to ask them to save her son. Tessa, using her ability to Change into Rosemary and access her memories, discovered that Rosemary and her husband had a planned location that she should go to should she ever need him. Following this knowledge, they went to the Los Angeles Shadow Market, where Tessa, once again Changed into Rosemary, went into the bar and waited for a sign to follow. After a conversation with the bartender, Tessa figured out her husband’s new alias however when she attempted to leave she was brought up short by Fal. Apparently, the faerie in the bar had recognized Rosemary and reported it to the Riders of Mannan. Fal stabbed Tessa despite Jem’s efforts to protect her.

For many days after this, Tessa was stuck in the Change — inconsistently switching between Tessa and Rosemary. When at last she regained control and awoke, Tessa told Jem how they could find Rosemary's son. They immediately returned to the Shadow Market, only to find no trace of Johnny. Eventually, they were able to get an address and they rushed to his home, only to find chaos — the remains of Johnny Rook’s body and Emma and Kit Rook fighting off a horde of Mantid demons. Jem joined Emma in fighting off the demons while Tessa got Kit out and told him of his lineage.

While they had initially planned to take him in, Tessa was called back to the Spiral Labyrinth to look into an illness plaguing warlocks around the world and Jem decided he should look for Malcolm Fade's body and find the Black Volume of the Dead. So instead they brought him to the Los Angeles Institute to remain safe for the time being.[15][11]


Later that year Jem attended the funeral for Livvy Blackthorn and Robert Lightwood. There he approached Emma with the news of Tessa’s pregnancy and concern over the warlock illness and that it may have ties to the ley lines Malcolm had used to raise Annabel Blackthorn. He requested she contact Catarina Loss when she went back to Los Angeles and look into the matter. Though that was not all that was concerning Jem; he had become worried that one of the Riders had recognized Kit and that he was in great danger. He asked Emma to look out for him and gave her a glass ring to use to summon him should she think that he was being hunted.

During the battle of The Cohort's parley, Jem and Tessa were tending to the wounded when they saw Kit unleash his powers upon the Riders. They immediately took him to the Silent City. After a few days of making sure Kit’s identity remained secret in Downworld, they came to him and asked him to come to live with them. Kit agreed and the three of them left for Cirenworth Hall.

They later briefly stopped by Magnus and Alec’s wedding. While they did not make their presence known, they watched from the cliffs.[16]

In March 2013, Tessa went into labor and they soon welcomed Mina Carstairs into the world.[17] A few months later, Jem took Kit with him to the New York Shadow Market. There they purchased something to help Mina with her teething. Later on, Jem and Church sat watching Kit practice. Eventually, Kit noticed and came over and ended up asking Jem to train him, which he agreed to.[18]


Jem comes across as kind, calm, gentle, quiet, exceedingly patient, and quite intelligent. He is also incredibly brave and strong and can be counted upon. He doesn't like to have people worrying about him and was especially secretive about his illness.

Physical description[]

While ill, Jem is described as being quite pale and having odd bright silver-colored hair, like an untarnished shilling. His eyes are said to be the same silver but with a gentle curve that hints at his parentage, and he has a fine-boned angular face, with a slight curve of his eyes. He looks youthful, partially because of his slightness. He is also tall, very slender and handsome too.

After he was cured of his illness, he is no longer pale as the color returns to his skin, his hair returns to dark brown, almost black, with only a single silver streak remaining, and his eyes are dark brown with gold flecks. Due to his stagnancy as a Silent Brother, Jem maintained his youthful appearance, looking like someone in his early twenties, though his wisdom and experiences in his long life as a Silent Brother reflects in his eyes. He has also since begun physically aging, after being cured.

Jem's parabatai rune, now faded to a pale white scar, is on his shoulder.[5]

Skills and abilities[]

  • Nephilim Physiology: Being Nephilim, Jem possesses a variety of enhanced physical and mental abilities granted to him by the blood of Raziel in his veins and also by the angelic Marks of the Gray Book. He also has the power to perform tasks unique to their species, such as the ability to use and call on the power of angels for their seraph blades. This includes enhanced strength, agility, stamina, and coordination, which only improves over time and practice.
  • Runic Magic: Due to the angel blood in their veins. All Shadowhunters are able to apply runes on their skin without any real danger. These Marks, in turn, give varied effects that serve to benefit the wearer.

  • Healing: As a Silent Brother, Jem was capable of healing others.
  • Telepathy: Though unable to speak, he possessed the ability to communicate with someone through their mind and sift through it as well.
  • Special runes: Though he could bear some of the strange runes unique to the Brothers, the yin fen in his body still did not allow him to bear some of the more powerful ones.
  • Longevity: As a Silent Brother, Jem became immortal for over a century and lost it only after being burned by heavenly fire, making him once again mortal.

  • Possessions[]

    • Stele: Jem uses a stele to draw runes on his skin for healing, etc.
    • Cane: A dragon-headed and jade-topped cane. Back when Jem was still sick, James used a cane as a walking stick in case he needed it for support. The cane also served as his weapon, with a blade hidden in it.
    • Jade pendant: Jem has had two kinds of jade pendants:
      • A green stone pendant made of jade that was in the shape of a fist. It had been a gift from Will, who gave it to him thinking it would remind Jem of his home and make him feel less homesick. Jem hung it on a chain and wore it as a necklace.
      • A smooth, circular, whitish-green jade pendant. It had Chinese characters carved into it; the writing, taken from the I Ching, the Book of Changes, reads "When two people are at one in their inmost hearts, they shatter even the strength of iron or bronze." It had been a gift to his mother from his father. He gave it to Tessa when he proposed to her, and she has worn it since.
    • Yin fen box: Jem kept his supply of yin fen powder in a silver box with the lid depicting Kwan Yin, the goddess of mercy and compassion, that once belonged to his mother.
    • Violin: Jem owned and primarily used the violin that was previously owned by his father and made by the luthier Giuseppe Guarneri.[19] After he left the Institute, the violin was left at the Institute but was well taken care of by Will.


    Tarot Runes 10
    I can offer you my life, but it is a short life; I can offer you my heart, though I have no idea how many more beats it shall sustain. But I love you enough to hope that you will not care that I am being selfish in trying to make the rest of my life—whatever its length—happy, by spending it with you. I want to be married to you, Tessa. I want it more than I have ever wanted anything else in my life.

    –Jem to Tessa, Clockwork Prince

    Jem developed feelings for Tessa shortly after they first met. Jem bonded with her, touring her around London. Some time after, Jem proposed to her, and the pair became engaged.[4] His desire to be with her made him want to take more of his yin fen, to be strong or seem healthy enough during their time together—a fact which angered and worried Tessa when she found out, knowing that it worsened his condition. When Mortmain threatened Jem's supply of yin fen and wanted Tessa in exchange for more, Jem refused to even consider surrendering Tessa.

    When Jem was made into a Silent Brother, they made a promise to meet once every year for an hour on the Blackfriars Bridge. They kept up with the meetings, missing only one meeting, despite Jem's general disposition during his time as a Silent Brother. When he was cured in 2008, Jem reunited with Tessa during their annual meeting and the pair resumed their interrupted relationship over a century before.[5][6] The pair began to travel and looked for the lost Herondale line.[11] Eventually, they also wedded.[6]

    Tarot Runes 7
    Will closed his eyes. He could not hear Jem go, not anymore; he did not want to know the moment when he left and Will was alone, did not want to know when his first day as a Shawdowhunter without a parabatai truly began. And if the place over his heart, where his parabatai rune had been, flared up with a sudden burning pain as the door closed behind Jem, Will told himself it was only a stray ember from the fire.

    Clockwork Princess

    When Jem first arrived at the London Institute, Will tried to intimidate him and drive him away with his moody attitude. However, when he saw that Jem was unfazed and patient, he became friends with him immediately, surprising Charlotte. Through the years they spent together, Will helped Jem with his illness and Jem helped Will in facing the world. Will did not tell Jem of the curse placed on him when he was twelve-years-old, although Jem knew that something was wrong. When they were fourteen-years-old, Will asked Jem to be his parabatai but Jem refused on the excuse that he was dying. But, after losing a bet with Will on a sword fight, he finally agreed. Will always bought Jem the yin fen because Jem could not face it himself. He cares for him when he is sick.

    Both Will and Jem came to fall in love with Tessa Gray, but Will relinquished his chances with her for Jem's sake at happiness. When a dying Jem discovered this, he was relieved rather than angry. He asks Will to rescue Tessa from Mortmain, and to be with her, protect her, love her, and keep her happy, now that he was unable to do so himself. Will was devastated when his parabatai link to Jem was broken, believing him to have died, though in actuality, Jem had become a Silent Brother. Leaving the Institute as Brother Zachariah, Will grew deeply heartbroken and fell into a depression for many months, though he eventually recovered. After his marriage to Tess, they both saw Jem occasionally. They would name their son after Jem and Will was insistent that only Brother Zachariah could place the protection runes on his child.


    For the appearances of his alter ego, please go to the separate page's own Appearances section.


    See more here


    • Jem is fluent in both English and Mandarin.
    • Jem's favorite weapon was a sword.[8]
    • Growing up, he had a cat named Xiao Long.[21]
    • Jem's favorite flavor of ice cream is maple walnut.[22]
    • His favorite flower is an orchid.[7]
    • Jem likes the music of the 21st century.[23]
    • Since first meeting him as Brother Zachariah, Lily Chen has come up with a number of objectifying nicknames for Jem; such as: Jem I'd-love-to-climb-'em Carstairs, Brother Zacharide-him-like-a-bad-pony, Brother Sixpackariah, Brother Hop-in-the-sack-ariah, Brother Mackariah, Brother Lipsmackariah, Brother Snackariah, Brother Let-him-see-my-rack-ariah, Brother Beast-with-two-backs-ariah, Jembalaya, Jem-nasium, and Peanut-butter-and-Jem sandwich. These names greatly amuse his wife and she has even begun using some of them.[24][14] It has also inspired others to come up with similarly formatted nicknames.[18]

  • Cindy Pon helped Cassie come up with Jem's Chinese name.[25]
  • In Clockwork Prince, Jem is said to be three months older than Will. However, in the 10th anniversary edition of Clockwork Angel, their birth dates were revealed as one month apart; causing a continuity issue.

  • References[]