In ancient Egypt where the gods live among the mortals, King Osiris is killed by his jealous brother Set during the coronation of Osiris's son Horus. Set then defeats Horus and takes his eyes, proclaiming himself the new king, and commands mankind to pay riches to pass into the afterlife.
One year later, with most of Egypt enslaved by Set, Zaya, a slave to Set's chief architect Urshu, gives plans for Set's pyramid to her lover, Bek. Using the plans, Bek infiltrates Set's treasure vault and steals one of Horus's eyes, but he and Zaya are caught by Urshu, who kills Zaya with an arrow as she and Bek escape. Bek takes her body to the exiled Horus along with the eye, promising to help find the other if he brings Zaya back from the dead.
They visit the divine vessel of Horus's grandfather Ra. Neutral about the conflict with Set, and at war with the shadow beast Apophis that threatens to devour the world, Ra does not restore Horus's power but allows him to take a vial of divine waters to weaken Set. Ra explains that Horus's loss of his powers is the result of not fulfilling his destiny, which Horus believes means avenging his parents' deaths.
Set asks Hathor to take him to the underworld, but she refuses and joins up with Bek and Horus. They hatch a plan to infiltrate Set's pyramid, recruiting Thoth to solve the riddle of the guardian sphinx. Overcoming the pyramid's entryway and the sphinx's riddle, they reach the source of Set's power. Before they can use the divine water, they are ambushed by Set, who destroys the divine water and takes Thoth's brain, but Horus saves Hathor and Bek. Hathor calls on Anubis to take Bek to the underworld and offers her bracelet as Zaya's payment for passage to the afterlife, sacrificing herself as doing so exiles her to the underworld.
Absorbing Thoth's brain, Osiris's heart, Horus's eye and wings from Nephthys, Set confronts Ra aboard his solar barge. Ra explains Set's mistreatment were tests to prepare him to take Ra's place as defender of the world against Apophis. Dismayed, Set decides to destroy the afterlife to become immortal, using his new powers to overpower Ra. Taking Ra's spear and casting him off the barge, Set frees Apophis to consume the mortal and underworld realms.
As Apophis attacks the gates to the afterlife are closed. Zaya, having refused Hathor's gift for not wanting an afterlife without Bek, encourages Bek to return to the mortal world and help Horus stop Set. As Horus battles Set atop an obelisk, Bek defeats and kills Urshu, before removing Horus's other eye from Set's armor, mortally wounding himself in the process and falling from the great height. Regaining his power to transform, Horus saves Bek from falling over retrieving his eye, and flies him to safety, realizing that his true destiny was to protect his people. With renewed strength, Horus outmaneuvers and kills Set. Finding Ra wounded in the aether, Horus returns his spear, allowing Ra to repel Apophis and Anubis to reopen the gates.
A child returns Horus's other eye and the god lays the deceased Bek in Osiris's tomb beside Zaya. For his deeds, Ra offers to bestow Horus with any power, and Horus asks that Bek and Zaya be brought back to life. Ra grants his wish and the other gods are restored, except Horus's parents, who had already passed into the afterlife. Horus is crowned king and declares access to the afterlife will be paid with good deeds in life. Bek is made chief advisor and gives Horus Hathor's bracelet. Horus leaves to rescue her from the underworld.
Nikolaj Coster-Waldau as Horus, the Egyptian God of Air, son of Isis and Osiris
Brenton Thwaites as Bek, a young thief who allies with Horus
Chadwick Boseman as Thoth, the Egyptian God of Wisdom
Élodie Yung as Hathor, the Egyptian Goddess of Love and Horus' lover
Courtney Eaton as Zaya, Bek's lover
Gerard Butler as Set, the Egyptian God of the Desert, brother of Osiris
Geoffrey Rush as Ra, the Egyptian God of the Sun, father of Osiris and Set
Bryan Brown as Osiris, the Egyptian God of the Afterlife, the king of Egypt and the father of Horus
Rufus Sewell as Urshu, Set's second-in-command and architect
In addition: Rachael Blake plays Isis, the wife of Osiris; Emma Booth plays Nephthys, sister of Isis and wife of Set; and Lindsay Farris provides as the voice of an older Bek, who narrates the film. Yaya Deng and Abbey Lee also appear as Astarte and Anat, goddesses of war who are loyal to Set.
Most of the 9 major Egyptian deities are portrayed in this movie.