Gorr, the last surviving member of a dying and forgotten people, drifts through a merciless desert with his young daughter, surviving only through exhaustion, faith, and desperation. He devotes himself entirely to prayer, believing his god Rapu will eventually answer and save them from starvation. But his devotion proves futile—his daughter dies in his arms from hunger and dehydration, leaving Gorr alone in a shattered world. In his grief, he hears a distant, almost divine call guiding him across the wasteland toward an oasis hidden from sight.

At the oasis, Gorr discovers Rapu living in comfort and abundance, having recently slain the previous wielder of an ancient cursed weapon known as All-Black the Necrosword. Rather than showing compassion, Rapu mocks Gorr’s suffering and dismisses him as insignificant, reinforcing the god’s cruelty and indifference. This final betrayal destroys Gorr’s faith completely. Enraged and broken, he seizes the Necrosword, which immediately bonds to him and begins corrupting his body while granting him dark, supernatural power. With it, he kills Rapu and swears an oath to eradicate every god in existence.

Meanwhile, Thor travels the cosmos alongside the Guardians of the Galaxy, acting as a wandering protector while trying to recover from years of loss, war, and emotional exhaustion. Though he continues to fight across the galaxy, Thor feels increasingly directionless and begins to question whether he should retire from heroism altogether. His internal conflict is interrupted when multiple distress signals emerge about a new god-killing entity named Gorr, including a desperate warning from Sif.

Thor and Korg respond to Sif’s distress call, finding her severely wounded after a brutal encounter with Gorr. She has lost an arm and warns them that Gorr is not only immensely powerful but is now targeting New Asgard. This revelation forces Thor back into action, even as he struggles with his own sense of purpose. At the same time, Dr. Jane Foster, battling stage IV cancer, travels to New Asgard in search of a potential cure through Asgardian magic, refusing to surrender to her illness.

Unbeknownst to Jane, Mjolnir—enchanted by Thor during their past relationship to protect her—responds to her presence across space. The shattered hammer reforms and chooses her as its new wielder, transforming her into the Mighty Thor and granting her godlike power. While she struggles to understand this transformation, Gorr launches an assault on New Asgard using shadow creatures forged from the Necrosword. Thor, Korg, Sif, and King Valkyrie arrive to defend the town, and Thor is stunned to discover Jane wielding Mjolnir.

Despite successfully repelling Gorr’s attack, the victory is short-lived as Gorr abducts the Asgardian children, including Axl, the son of Heimdall. Using Axl’s psychic connection, Thor learns the children have been taken to the Shadow Realm. Realizing the gravity of the situation, Thor, Jane, Valkyrie, and Korg determine that they must seek assistance from the gods themselves. They journey to Omnipotence City, a realm where deities from across the universe gather in opulent isolation, in hopes of forming an alliance against Gorr.

In Omnipotence City, they seek audience with Zeus and other gods, warning them of Gorr’s impending attack. However, Zeus dismisses the threat entirely, revealing the gods’ arrogance and detachment from mortal suffering. When Thor presses further, Zeus has him imprisoned, sparking a chaotic confrontation. In the ensuing struggle, Zeus injures Korg with a thunderbolt, leaving him barely alive, while Thor retaliates by using Zeus’s own weapon to wound him. The group escapes, with Valkyrie taking possession of Zeus’s thunderbolt. During this journey, Thor learns of Jane’s worsening cancer, and the two quietly rekindle their emotional connection.

The heroes track Gorr to the Shadow Realm, only to realize they have walked directly into a trap. Gorr reveals his true objective: to take Stormbreaker and use it to access Eternity, the cosmic entity capable of granting a single wish. A battle erupts, but Gorr overwhelms the team and steals Stormbreaker, forcing them into retreat. Thor also learns that Jane’s continued use of Mjolnir is accelerating her cancer, but she refuses to abandon the fight, determined to stand beside him until the end.

At the center of the universe, Gorr begins opening the gateway to Eternity using Stormbreaker. Thor arrives wielding Zeus’s thunderbolt and empowers the captured Asgardian children, turning them into temporary warriors against Gorr’s shadow monsters. The battle escalates as Gorr overpowers Thor, forcing Jane to re-enter the fight despite her rapidly declining health. Riding Valkyrie’s winged horse, she joins Thor in a final stand and helps destroy the Necrosword, weakening Gorr but sealing her fate.

In her final moments, Jane collapses in Thor’s arms as cancer overtakes her, and she later ascends peacefully to Valhalla. Thor confronts Gorr at Eternity and pleads with him to choose love over vengeance. This emotional appeal reminds Gorr of his own lost daughter, leading him to abandon his genocidal wish. Instead, he uses Eternity to resurrect his daughter, choosing love over destruction. As the Necrosword’s corruption consumes him, Gorr dies and entrusts his daughter’s safety to Thor.

In the aftermath, New Asgard rebuilds and honors Jane with a statue as the Mighty Thor. Valkyrie and Sif begin training the Asgardian children for future defense, while Korg fully regenerates and continues his life among them. Thor becomes a father figure to Gorr’s daughter, raising her as his own and passing Stormbreaker to her while he continues wielding Mjolnir. Together, they travel the cosmos as “Love and Thunder,” protecting those in need. Meanwhile, Zeus, humiliated and wounded, sends his son Hercules to hunt Thor in revenge. In Valhalla, Jane is reunited with Heimdall, finally finding peace in the afterlife.