Tessa Gray
Tessa Gray
Biographical Information
Full name: Theresa Herondale-Carstairs (née Gray)
Born: 1862
New York
Age: 147 (as of 2009)
Status: Immortal
Also known as: Tessa
Tess (by Will)
Tessie (by Nate)
Species: Half-Eidolon demon
Residence: Los Angeles (as of 2008)
Paris (former)
London Institute (former)
New York City (former)
Allegiance: Enclave
Family: Aloysius Starkweather † (great-grandfather)
Unnamed Eidolon Greater Demon (father)
Elizabeth Gray † (mother)
Richard Gray † (foster father)
Jem Carstairs (husband)
Will Herondale † (first husband)
James Herondale (son)
Lucie Herondale (daughter)
Cecily Herondale (sister-in-law)
Anna Lightwood (niece-in-law)
Christopher Lightwood (nephew-in-law)
Alexander Lightwood (nephew-in-law)
Harriet Moore † (adoptive aunt)
Nate Gray † (adoptive brother/cousin)
Starkweather family
Herondale family
Carstairs family
Physical Description
Gender: Female
Hair color: Brown
Eye color: Gray
Height: Around 5'8"
I am Theresa Gray, daughter of a Greater Demon and Elizabeth Gray, who was born Adele Starkweather, one of your kind. I was the wife of William Herondale, who was the head of the London Institute, and I was the mother of James Herondale and Lucie Blackthorn. Will and I raised our Shadowhunter children to protect mundanes, to live by the Laws of Clave and Covenant, and to keep to the Accords. Once, I lived among the Shadowhunters. Once I might almost have seemed like a person to you.

–Tessa to Jocelyn in 1993, The Last Stand of the New York Institute

Theresa "Tessa" Gray is an American warlock, particularly a new kind of warlock—the rare half-Shadowhunter, half-Eidolon demon. After arriving in London and becoming entangled in the lives of the Shadowhunters at the London Institute during the Victorian era, Tessa married the Shadowhunter Will Herondale.


Early lifeEdit

Theresa Gray was born to an unmarked Shadowhunter named Elizabeth Gray and an Eidolon demon, but raised by who everyone believed to be her father, the mundane Richard Gray. Under normal circumstances, children of Shadowhunters and demons would be stillborn, but Elizabeth was able to give birth to Tessa not only because she bore no runes, but also because she wore the clockwork angel.

For much of her early life, she was unaware of what she truly was and her true parentage. Conceived in London, Tessa's family moved to New York while Elizabeth was pregnant with her. After the death of her parents in a carriage accident when she was only three years old, she and her brother, Nate, were raised by her maternal aunt, Harriet Moore. She spent the majority of her life being overprotected by her Aunt Harriet and looking after Nate, who grew up spoiled. Tessa grew up taking comfort in books, dreaming of having the kind of adventures she read about. At sixteen, her Aunt Harriet died of what she thought was a fever. Upon her death, Nate arranged for Tessa to move to London with him.

Arrival at LondonEdit

Tessa traveled from New York to London when Nate called for her, shortly after the death of their Aunt Harriet. Once there, a pair of mysterious and sinister women, whom she called the Dark Sisters, gave her a letter written in Nate's handwriting and told her that they've come to collect her on Nate's behalf.

The Dark Sisters soon revealed that they apparently had Nate as a prisoner, showing her their father's ring, one that Nate always wore, splattered with blood. They forced her to Change, or shape-shift, torturing her to learn quickly as well as threatening to harm Nate if she did not do as they asked. The Dark Sisters had made a deal with "the Magister" who had hoped to marry her and exploit her ability. In her isolation, she wrote letters to Nate about her loneliness and imprisonment, which Will later found and read.

One day, after Changing into Emma Bayliss, she was told about her marriage arrangement with the Magister, who had long been waiting for her. After a futile attempt of escape, she was finally rescued by the Shadowhunter Will Herondale. Tessa passed out in the midst of the fight against the Dark Sisters and was taken to the London Institute.

During her stay at the Institute, the head Charlotte Branwell promised to take care of her and help her search for Nate. There, Tessa befriended Jem Carstairs and the rest of the Institute's residents and staff, particularly Sophie Collins, the handmaid, while she had an uneasy relationship with Jessamine Lovelace, who wanted to move out of the Institute with Tessa.

When the investigation into her brother led them to Alexei de Quincey's house, she took the form of the vampire Camille Belcourt to infiltrate an exclusive party, with Will posing as her human subjugate and Magnus Bane, Camille's lover, as her guide. Once the human captive at the party was bitten, Will sent a signal to the Nephilim lying in wait to attack. Tessa then realized that the captive human was her brother, Nate.

During the battle, de Quincey went after Tessa, who was still in the form of Camille. Will, to save Tessa, fought him and ended up biting the vampire. After the battle, Nate was brought back to the Institute, where he was questioned and allowed to recover. Tessa got only a few moments with Nate since Jessamine, who wanted to marry a mundane so she can leave the Shadowhunter world, seemed insistent on caring for him instead, hoping Nate will fall in love with her.

Later, Tessa learned from Sophie that Will was being difficult about his treatment, which involved drinking buckets of holy water to bring up the vampire blood he had ingested, or else he would become a darkling. Tessa volunteered to take it to him in the attic, and Will finally obliged. During their rather intimate conversation, they shared their first kiss, before Will pushed her away and insisted that she leave him. After this evening, Will became even more standoffish and unfriendly towards her, much to Tessa's confusion.

To her surprise the following day, the Shadowhunters were discussing the further interrogation of Nate, possibly by the Silent Brothers. Annoyed, Tessa made it clear that their goals are not her responsibility, and that she did her part as they searched for Nate. Before leaving, she called them out for their pretentious attitude towards Downworlders and mundanes. After having some time to feel sorry about shouting at them, particularly since she was primarily only mad at Will, she left the Institute. She was promptly followed by Jem, who then began pointing out some places in London that might help her learn to love the city and even took her to his favorite—the Blackfriars Bridge. Here, Jem told her bits of his and Will's story and told her that he thinks she is no less human than him.

Unbeknownst to them, they were followed by a pair of automatons, one of them the being the clockwork coachman of the Dark Sisters, under the Magister's orders. Jem briefly engaged them before running off with Tessa and got as far as the Institute before Jem collapsed, his illness striking at a bad time; fortunately, Charlotte immediately came to their rescue. During Jem's recovery, he told her about his illness, his body's dependence on yin fen, so she wouldn't blame herself.

Mortmain revealedEdit

When Nate woke up, he quickly devised a plan that he secretly told the Magister of but continued to bear the semblance a frightened boy who wanted nothing more than to go home with Tessa and live a normal life. Selling her and the others lies and some half-truths about the true nature of his business in London, Nate falsely told them that de Quincey really was the Magister, and that the Dark Sisters would perform the binding ritual, a spell that would improve the automatons that Magnus Bane had previously told them about, on a full moon—that same evening.

Because of the assumption that de Quincey's plan of taking over London would commence that evening, the Enclave decided to act. After they left, Will and Jem were put in charge of the Institute. Mortmain paid them a visit the same evening and fed them false information about De Qiuncey's plans. Will and Jem got a hold of that hint and took off, leaving the Thomas to protect the Institute. However, Axel Mortmain intentionally provided the wrong information in order to attack the Institute and take Tessa with him, as he was revealed to be the Magister. That was when they found out about Nate's deal with the Magister.

When confronted by the Magister, Axel Mortmain, Tessa recalled Will's words to her earlier, explaining that the British warrior-queen Boadicea was braver than any man because she killed herself rather than let herself be taken by the Romans. With this inspiration, she prepared to kill herself to escape Mortmain. However, she realized that if she Changed into the form of a dead woman, particularly Adams, whose form she had already taken while under the tutelage of the Dark Sisters, she would bleed convincingly. By Changing very quickly, and for a very short time, into a woman who had been shot, she convinced Mortmain that she was dead and he left when confronted by Will.

Will was momentarily affectionate, but then put an even greater distance between them. Later, she confronted Will, hoping to reconcile, but he was unkind, treating her like a prostitute and revealed that she was unable to have children as she was a warlock. Tessa left, hurt and confused.

Over the next couple of weeks, Tessa grew closer to Jem, who volunteered to keep touring Tessa around London.

Tessa was present, and was a key witness, at the trial of Charlotte Branwell in front of the Clave, about the attack on the London Institute. Charlotte was given two weeks to find Mortmain or she would have had to resign as head of the Institute, and be replaced by Benedict Lightwood.

Tessa, accompanied Will and Jem, up to the York Institute to meet Aloysius Starkweather, who may hold a clue to the Magister's past. Jem gave her the Carstairs family ring, so that she could pretend to be a mundane girl, who was engaged to Jem.

Tessa was trained by Gabriel Lightwood to defend herself, in case there was an attack against the London Institute.

Sophie Collins came to Tessa with an invitation to a masked ball at the Lightwood's house, addressed to Jessamine from Nate. Jessamine slapped Sophie when she saw Sophie with it, so Sophie hit and knocked her out. Tessa sent Sophie to Will for help, and he placed a sleeping rune on Jessamine so that she would not wake up until morning, and tied her to her bed as a precaution. Tessa Changed into Jessamine, and Will accompanied her, so that she could sneak into Benedict Lightwood's house. Tessa met Nate, who danced with Jessamine, and reminded her that she was now 'Jessamine Gray'.

On the balcony at Benedict Lightwood's estate, Tessa and Will shared a rather intimate moment, which was interrupted by Magnus Bane. He was the one who helped them to get back outside of the house.

Later, Tessa once again Changed into Jessamine to meet Nate in a warehouse. However, that was a trap, as Nate had recognized his sister. Afterwards, Tessa was severely injured and Nate was fatally wounded.

Jem proposed to Tessa, and gave her his mother's jade pendant as a token of their engagement. However, Will arrived back from Magnus' house after the demon, Marbas, revealed that there was no curse on him. He talked to Tessa in private and declared his love for her, but she rejected him and told him that she was engaged to Jem.

Imprisoned by MagisterEdit

Sometime after weeks of preparing for the wedding, Tessa finally realized that she was half-Shadowhunter, half-demon—an entirely new hybrid and immortal species that Mortmain wanted to progenerate with her.

She was kidnapped in an assault on the Institute at the delivery of Jessamine from the Silent City where she was taken to the Magister, who had taken up refuge in Cadair Idris near Will and Cecily's former home. Will then came and found them, but his long trip was to no avail as he was captured by his own stupidity and Mortmain's invisible wall. The rest of the Enclave then showed up, accompanied by three Silent Brothers: Enoch, Micah, and Zachariah.

In the fight with the Infernal Devices, it was revealed that her fiancé, Jem, had become a Silent Brother, Brother Zachariah. Since Silent Brothers cannot marry, they were separated.

Tessa eventually married Will, and the two stayed together for at least 60 years. When around strangers, Tessa glamoured herself to appear older and look around the same age as Will. During their thirtieth wedding anniversary, Will took the bracelet Tessa wore on their wedding, which bore the wedding runes she could not, and had it redesigned with pearls.

Tessa stayed with Will until his death in 1937. Afterwards, Tessa left London and momentarily stayed in Paris with Magnus, who helped her cope with her losses. While she hoped not to have to go through the pain of seeing her own children grow old and die, she remained in contact and still visited them and her grandchildren often. She also went back to using 'Gray' as her surname.

Labyrinth refugeEdit

Tessa began traveling at one point, staying particularly long at Los Angeles, where she kept an eye on her daughter's descendants, the Blackthorns, from afar.

Two years after the Uprising, Tessa was staying with Magnus in New York when Jocelyn Fairchild came to ask him to protect her daughter, Clary. Tessa, in the place of an Iron Sister, then performed the Shadowhunter children's ritual on Clary with Brother Zachariah. Pleased to meet her, Jocelyn took up the surname "Fray", a portmanteau of Fairchild and Gray, in honor of Tessa's friendship with her ancestors.

Saddened by the Uprising, and the thought that the Herondales, the line of her and her husband, were gone, Tessa retreated to the Spiral Labyrinth and spent most of her time there, away from the rest of the world and its troubles. She instead focused on her research as a more scholarly warlock, aiding the Nephilim on occasion.

In September 2007, Tessa participated and fought in the Mortal War at Alicante. Some time after the battle, she found out that Stephen Herondale's son, Jace, was in fact alive. She hoped to speak with him, though Magnus told her to give him some time to accept his own lineage before she burdens him with the past. While speaking with Magnus, Clary noticed her and even vaguely remembered her, thinking she was familiar, but did not remember from when. At that time, Tessa was wearing white, mourning certain deaths, such as Ragnor's. Tessa returned to the Labyrinth afterwards.

Full circleEdit

In January 2008, during their annual meet-up at the Blackfriars Bridge, Jem surprised her by arriving as a mortal, no longer a Silent Brother nor dependent on his yin fen as he has been cured by Jace Herondale and his heavenly fire. Though surprised, Tessa welcomed him back into her life wholeheartedly, and the pair rekindled their relationship, sharing a kiss at the bridge. They agreed to see the world together, and Jem told her the "story of Lightwoods and Herondales and Fairchilds".

In May, they attended the wedding of Jocelyn and Luke. There, Jocelyn formally introduced her to Clary, who slightly recognized her. During the conversation, Tessa told Clary that she felt a kinship towards their families, and gave her her copy of the Shadowhunter's Codex, as well as the Herondale family ring that was once her son's, James, to pass onto Jace. While Jace has finally accepted the Herondale name, she, and Magnus, still opted to give him a bit more time to adjust and be happy on his own.

The following year, she and Jem got married at London, on the Blackfriars Bridge, attended by their new friends, as well as old ones—the ghosts of Jessamine and Will.

Personality and traitsEdit

Tessa is an intelligent person. She is brave and strong-willed, and is incredibly caring. While she is generally warm, kind and understanding, Tessa can sometimes be very stubborn. She is also immensely curious and intensely determined when she decides to be.

Physical descriptionEdit

Tessa has smooth, thick, wavy brown hair, steely gray-blue eyes, an oval face, and a slender body. She is considerably taller than most girls and boys her age (before she stopped aging). While she used to think herself average, several of her friends have noted that Tessa is pretty and beautiful; not conventionally beautiful, but kindly attractive. Being immortal, Tessa stopped aging young and appears like a young woman in her early twenties.

According to Aloysius Starkweather, she looks very similar to her maternal grandmother.

Skills and abilitiesEdit

  • Immortality: Tessa is immortal, having maintained her youthful appearance since the 19th century.
  • Magic: After gaining the ability to perform basic warlock magic, Tessa began practicing magic over the years and has even spent some time researching among warlocks at the Spiral Labyrinth.

  • Changing: As a child of an Eidolon demon, she has inherited the ability to Change; the demonic power to shape-shift into another person. Unlike ordinary Eidolon demons like Mrs. Dark, Tessa can become whomever she transforms into as long as she has a physical object of theirs when she first turns into them. She achieves the Change by linking with a psychic impression or remnant of a person contained within an object. She can also Change by linking with a person's soul, as she did when she Changed into the Angel Ithuriel. In addition to their physical presence, Tessa is also able to touch the mind of a person and access their memories and thoughts when Changing, taking on their memories, mannerisms, and abilities.
    • After the events in Cadair Idris, Tessa's powers changed due to the heavenly fire. "There are some things she can no longer do, and some things she can do that she couldn't do before. She can no longer read the minds of people when she changes into them; however, she can do some basic warlock magic she couldn't before."


  • Clockwork angel: the clockwork pendant designed to protect her. It was given to Tessa's mother by Mortmain. It contained Ithuriel's soul and when the angel was freed, Tessa stopped wearing the necklace.
  • Jade pendant: the whitish-green pendant Jem gave Tessa when he proposed to her. It was first given to his mother by his father. It has Chinese characters carved into it which translates to "When two people are at one in their inmost hearts, they shatter even the strength of iron or bronze," from the I Ching, the Book of Changes.
  • Pearl bracelet: the bracelet Tessa wore for her wedding with Will. The marriage runes were placed on the bracelet instead of her skin. On their thirtieth wedding anniversary, Will had it redesigned with pearls.



Will had his arms around her and her hand was in Jem’s. That was enough to keep her breathing.

The Whitechapel Fiend

Will Herondale was Tessa's first husband. They married and stayed together for a long time until Will's death.

Jem Carstairs is Tessa's current husband. Before he joined the Silent Brothers, they were engaged. When Jem was restored to his former, mortal self, he proposed to Tessa on Blackfriars Bridge and they immediately resumed their relationship.


Along with other warlocks Catarina Loss and Ragnor Fell, Tessa has become very close with Magnus Bane.


Tessa's parents died when she was quite young. Nonetheless, the few years they raised her were said to be full of love.

Tessa used to have a good relationship with Nate until he grew bitter and dissatisfied with his life. He became seemingly indifferent towards her, even willing to sacrifice her free will in exchange for his success—a revelation that shocked and hurt her. Despite this, Tessa loved her adoptive brother dearly and mourned his death, and even Nate seemed to express some remorse before then.

Harriet is Tessa's aunt, though not by blood—a fact neither knew during their time together. Harriet raised her lovingly, as she did her own child, after the Elizabeth's death.

Tessa's descendant.




  • Tessa hates chocolate.
  • Tessa always wore the pearl bracelet given to her by Will on their thirtieth-anniversary and the jade necklace given to her by Jem when he proposed to her.
  • As of the 21st century, Tessa apparently has around fifty living descendants.
  • Tessa chooses to go by her "warlock name", a one syllable surname, Gray, as she does not want to be identified as a Shadowhunter, despite technically being a Starkweather by birth, and a Herondale and Carstairs by marriage.
  • Jocelyn Fray formed their mundane surname "Fray", a portmanteau of Fairchild and Gray, as an homage to Tessa and her close relationship with the Fairchilds.
  • Tessa, like Clary, is a main protagonist and narrator in Cassandra Clare's book series. In the first book, both are attacked and knocked unconscious by demons and are brought to the Institute by one of their potential love interests, particularly Will for Tessa and Jace for Clary. Both also walk in on their love interests playing a musical instrument in a room at the Institute; Jem was playing violin, and Jace was playing the piano, and both mistook the girls to be their parabatai before seeing them.
  • Tessa's original surname was Fell, before the name was given to Ragnor Fell.
  • She is around 5'9 which was tall for a girl at that time.
  • Due to having Shadowhunter blood, Tessa is seemingly immune to the harmful effects of runes, as Charlotte mentioned they had attempted to use healing runes on her. The ink merely sank into her skin.