Jane Foster is one of the Marvel Universe's oldest supporting characters, predating even the Avengers. Created by plotter Stan Lee, scripter Larry Lieber, and legendary artist Jack Kirby, she first appeared in Journey into Mystery #84 (September 1962). Initially, she served as a nurse for Dr. Donald Blake, the mortal guise of Thor, and was the primary romantic interest and link to humanity for the Asgardian prince. For decades, her character evolved from a classic damsel-in-distress to a skilled physician in her own right, but she remained largely on the periphery of Thor's superheroic adventures. The modern, revolutionary chapter of her story began with writer Jason Aaron's epic run on the Thor titles. The concept of a new, female Thor was seeded in the 2014 crossover event Original Sin, where Nick Fury whispered an unrevealed secret to Thor Odinson that made him instantly unworthy to wield Mjolnir. This set the stage for a new beginning. In Thor (Vol. 4) #1 (October 2014), a mysterious woman picked up the abandoned hammer and became the new Goddess of Thunder. Her identity was kept a secret from both readers and the characters in the Marvel Universe for several months, creating a compelling mystery. It was not until Thor (Vol.4) #8 (May 2015) that she was revealed to be Jane Foster, now a doctor battling breast cancer. This iteration of the character was co-created by writer Jason Aaron and artist Russell Dauterman, whose dynamic art defined her tenure as Thor. This storyline was met with critical acclaim for its depth, emotional resonance, and powerful exploration of heroism in the face of mortality.
The circumstances of Jane Foster's ascension to godhood differ significantly between the prime comic continuity and the cinematic universe, though they share core thematic elements of illness and sacrifice.
Jane Foster's journey to becoming Thor was born from two simultaneous tragedies: Thor Odinson's fall and her own mortal struggle. During the Original Sin event, a confrontation with Nick Fury armed with the knowledge of the Watcher resulted in Fury whispering something in Thor's ear that shattered his self-worth. Whatever the secret was 1), it caused Thor to instantly become unworthy, unable to lift his own enchanted hammer, which he had left on Earth's moon. At the same time, Dr. Jane Foster had been diagnosed with breast cancer. She pursued aggressive chemotherapy, but the treatment was debilitating. As a renowned physician, she was acutely aware of her own prognosis. Thor Odinson, now just “Odinson,” had visited her, even offering Asgardian magical cures, which she staunchly refused. She insisted on fighting her battle on her own human terms, believing that magical “cheats” would invalidate the struggle of every other cancer patient. Sensing Odinson's unworthiness and a profound need in the universe, Mjolnir began to telepathically call out. Jane, feeling a strange pull, was eventually able to arrange transport to the Moon's location with S.H.I.E.L.D. There, on the barren lunar surface, lay the hammer. Hesitantly, she reached for its handle. The moment her hand touched the Uru metal, a bolt of lightning struck, and she was transformed. She was imbued with the power of Thor, clad in new armor, and held the might of the storm in her hands. She quickly discovered that Mjolnir had a will of its own and seemed to respond to her thoughts with an unprecedented level of speed and agility. However, this immense power came at a terrible cost. Each time she transformed into Thor, the magic of Mjolnir purged all toxins from her body. Tragically, it identified the life-saving chemotherapy as a poison, rendering her treatments useless and allowing the cancer to advance unchecked within her human form. Jane kept her identity secret for a long time, even from Odinson, who respected the new Thor's right to privacy while conducting his own investigation. She joined the Avengers, served as a senator for Midgard in the Congress of Worlds, and fought countless battles against foes like Malekith, the Absorbing Man, and even Odin himself, who refused to accept a “pretender” wielding Mjolnir's power. Her every heroic act was a countdown, a step closer to her own death, a sacrifice she willingly made for the good of the Ten Realms.
The MCU's adaptation of Jane's story, primarily depicted in Thor: Love and Thunder, streamlines her origin while retaining the core emotional conflict. Years after her relationship with Thor ended, Dr. Jane Foster is a world-famous astrophysicist. However, she is diagnosed with Stage Four cancer and finds that conventional medical treatments are failing to stop its progression. Desperate and running out of options, her research into ancient mythologies leads her to a potential cure: the mystical power of Thor's hammer, Mjolnir. She travels to New Asgard, now a tourist destination on Earth, where the fragments of Mjolnir—shattered years prior by Hela in Thor: Ragnarok—are on display. Unbeknownst to Jane, years before, Thor had lovingly spoken to Mjolnir, asking it to promise to always protect her. The hammer, imbued with this lingering enchantment, sensed her presence and her desperate need. As she neared the display, the fragments began to glow and levitate. They swirled around her, re-forming into a complete hammer and wrapping her in armor of lightning and steel. She was transformed into The Mighty Thor. This origin differs from the comics in several key ways:
Much like her comic counterpart, Jane soon discovered the terrible price of this power. Wielding Mjolnir was not curing her cancer; it was draining her life force, preventing her body from fighting the disease. The power was using up her remaining time, forcing her to choose between living a little longer as a mortal or fighting for the universe as a god, knowing it would be the end of her.
As The Mighty Thor, Jane Foster possessed all the traditional powers bestowed upon a wielder of Mjolnir, but she also demonstrated unique capabilities and a different approach to her powers shaped by her intellect and the hammer's unique connection to her.
Jane as Thor was defined by a deep well of compassion mixed with fierce determination. Unlike the often-boisterous Odinson, she was more measured and thoughtful, likely a result of her background as a doctor. She fought to save everyone and felt the weight of every life she couldn't protect. She was humbled by the power she wielded and acutely aware of its temporary nature, which drove her to do as much good as possible in the time she had left. She possessed an inner strength that impressed even the gods.
The MCU's Mighty Thor shares many abilities with her comic-book counterpart but with distinct visual flairs and a slightly different context for her powers and weaknesses.
Natalie Portman portrayed Jane with a mix of her established scientific brilliance, newfound awkwardness with her powers (“What's a catchphrase?”), and a desperate, underlying fear of her own mortality. She was driven to find a “godly” solution to a human problem, and when she got one, she embraced the heroic role with gusto. She retained her wit and charm, but it was layered with the tragic knowledge that her time as a hero, and a human, was running out. Her final decision to help Thor fight Gorr, despite knowing it would kill her, showcased her ultimate selflessness.
This storyline establishes Jane's entire arc. It begins with Odinson's unworthiness and Mjolnir abandoned on the moon. The mystery of the new female Thor's identity drives the narrative for eight issues. We see her learning to use her powers, battling Frost Giants and Malekith, and earning the respect of other heroes, all while facing intense scrutiny from a furious and suspicious Odin. The reveal of her identity as a cancer-stricken Jane Foster in issue #8 is a watershed moment, re-contextualizing her heroism as something deeply personal and sacrificial. It established the core theme of her story: what does it mean to be a god when you are so painfully, finitely human?
This is the climactic, heartbreaking finale to Jane Foster's time as Thor. The unstoppable Mangog is unleashed upon Asgardia, the city of the gods then floating over Oklahoma. One by one, Asgard's greatest defenders—Heimdall, the Warriors Three, even Odin himself—are brutally defeated. Odinson, wielding the axe Jarnbjorn, is also cast aside. Doctor Strange tells Jane that one more transformation into Thor will kill her for good. Faced with the annihilation of a people and a realm she swore to protect, Jane makes her choice. She utters the words “I am Thor” one last time, and engages the Mangog in a cataclysmic battle. Knowing she cannot destroy it by conventional means, she wraps it in chains she summoned from the core of Asgardia, binds them to Mjolnir, and flings the hammer—and the monster—into the sun. The act destroys the Mangog and Mjolnir, and as the divine magic fades, Jane Foster dies a hero in Odinson's arms. 2)
While Jane was no longer Thor during this massive crossover event, her role was still pivotal. The story is the culmination of Jason Aaron's entire saga, as Malekith brings his war to its final battleground: Midgard. At the start of the war, Jane is a human, deep in her cancer treatment. She acts as a voice of hope and reason for the people of Earth. However, as the war rages and the Valkyries are all slaughtered, Jane steps up. In the wreckage of the battle, she finds the shattered remains of the Valkyries' weapons. They coalesce around her, forming Undrjarn the All-Weapon, and she becomes the new Valkyrie, rejoining the fight not as a god of thunder, but as a chooser of the slain and a warrior of immense power, proving her heroism was never tied to Mjolnir alone.
During the 2015 Secret Wars event, the multiverse was destroyed and reformed into a single planet, Battleworld, ruled by Doctor Doom. The police force of this planet was the Thor Corps, an army of different Thors drawn from across the dead multiverse. While Jane Foster of Earth-616 was not a member, this event introduced several other female Thors, most notably the “Ultimate Thor” from Earth-1610, who was a key character in the miniseries. This event broadened the conceptual possibility of “Thor” being a title held by many, paving the way for wider acceptance of Jane's role.
In the MCU animated series What If…?, a variant of Jane Foster appears in the episode “What If… Thor Were an Only Child?”. In this reality, Thor is a hard-partying prince who throws a planet-wide rager on Earth. Jane is the brilliant astrophysicist who discovers his arrival, but in this timeline, she becomes his love interest without the drama of his banishment or the Mjolnir conflict. She plays a key role in helping him clean up his mess before Frigga arrives. This version showcases a lighter, purely romantic path their relationship could have taken.
Jane Foster was added as a playable character to the 2020 Marvel's Avengers video game. Her story in the game is an alternate-reality take, drawing heavily from her comic book origins. In her timeline, following A-Day (the game's inciting incident), Jane became Thor after Odinson grew disillusioned. She was eventually pulled into the game's prime reality, where she fights alongside the Avengers, including the prime version of Thor. Her gameplay and abilities are a direct homage to her comic book run, emphasizing her unique and acrobatic control over Mjolnir.