SPOILER WARNING: Plot details follow. Caution is advised!
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 was 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.

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 course of 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 favourite 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 light 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 witnessesed 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 had 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.[1]

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.[2]

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 blackmaild 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.[3]

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.[4]

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.[4][3] The same day, the couple went to Tessa's flat in London, where Jem soon lost his virginity.[5]

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.[6] 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."[7]

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.[4]

The following year, he and Tessa got married at London, on the Blackfriars Bridge, attended by their new friends as well as old ones—the ghosts of Jessamine and Will.[8] For some reason, however, most of the guests do not remember the wedding.[9][10] He also later attended Emma's parabatai ceremony with Julian Blackthorn. There, he finally told Emma about him being a Carstairs.[11][10]

Jem and Tessa then set out to look for Tobias Herondale's descendants. They were eventually able to track down the family, with difficulty given its various name changes over the years. They found Johnny and Kit Rook in August 2012, with Johnny hiding his son among mundanes, keeping the secret of their heritage from him. When Johnny died, they finally approached Kit and asked him to stay at the Los Angeles Institute where he could be kept safe.[10]


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.[3]

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 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.


  • 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.[12] 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.[2] 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, for one hour. 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.[3][4] The pair began to travel and looked for the lost Herondale line.[10] They were also eventually wed.[4]

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 arrives at the London Institute, Will tries to intimidate him and drive him away by his moody attitude. But when he sees Jem to be unfazed and patient, he becomes friends with him immediately, surprising Charlotte. Through the years they spend together, Will helps Jem with his illness and Jem helps Will in facing the world. Will does not tell Jem of the curse put on him when he was 12, although Jem knows something is wrong. When they were 14, Will asked Jem to be his parabatai but Jem refused on the excuse that he was dying. But after loosing a bet with Will on a sword fight, he finally agreed. Will has always bought Jem the yin fen, because Jem couldn't face it himself. He cares for him when he is sick.

Even though Will loves Tessa, he gives her up for the sake of Jem. When Jem finds out, he is relieved instead of angry, and asks Will to go save Tessa and be with her an protect her and love her and keep her happy, for he can't do it himself.

When he leaves the Institute as a Silent Brother, Will is deeply heart-broken and falls into a depression for months, but finally recovers. After his marriage to Tessa, they both see Jem only occasionally


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 is three months older than Will.[2]
  • Jem's favorite weapon was a sword.[6]

  • Jem likes the music of the 21st century.[14]
  • Cindy Pon helped Cassie come up with Jem's Chinese name.[15]
  • Jem's favorite flavor of ice cream is Maple Walnut. [16]


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