|“||Am I not an Iron Sister? Did I not take the vows? Do my hands not shape the stuff of Heaven?||”|
–Magdalena, City of Lost Souls
Born a Shadowhunter, Magdalena lived and grew up in Idris. For unknown reasons, Magdalena joined the Iron Sisters and eventually also joined the Circle. Magdalena opted to keep her involvement with the organization a secret, knowing that, as an Iron Sister, she was supposed to be a loyal servant to the Clave, one who was not even allowed to leave the Adamant Citadel, where Iron Sisters reside. Magdalena was commissioned by Valentine Morgenstern to craft the weapons of the Circle—weapons with demonic alliances that went undetected in the Accords Hall.
When the Uprising failed, Magdalena fled, knowing that she would be disgraced if her part in the Uprising was to be discovered. She fled the Citadel and was without a supply of adamas for many years. Magdalena spent the next seventeen years in France and avoided contact with other Shadowhunters, living out her life in solitude.
Magdalena was contacted after seventeen years by Sebastian Morgenstern, Valentine's son. He requested that she make a second Mortal Cup using pure adamas that he had retrieved from a demon seller, with the help of Clary Fray and Jace Herondale.
When Magdalena completed the Infernal Cup, Jace was sent by Jonathan to retrieve the cup and kill Magdalena to prevent her from making another similar object and speaking about what she had created to anyone else. This took her by surprise, but she managed to wound Jace, even damaging the rune that bound him to Jonathan. Jace woke from his daze to find himself standing over Magdalena's dead body.
Horrors in Edom
After her death, Jace was seemingly haunted by the fact that he'd murdered her, though unwillingly. While in Edom, Jace was approached by a demon that took her form; the demon goaded him into losing control, telling him that "she" was cursed for her betrayal to roam Edom forever, always wounded and bleeding, after he had killed her, and continued to taunt him with details of his life. The demon managed to upset Jace so much that he lost control of the heavenly fire within him and blazed up, killing it.