Horace Holly is a Cambridge professor who raises his friend's kid after his mysterious death. He raises Leo, and when Leo turns 25, they open a box together that was left for Leo by his father, and thry discover an ancient document called "Sherd of Amenartas." Horace and his god-son Leo travel with a servant named Job to eastern Africa to learn more about the Sherd of Amenartas, but they are shipwrecked.
With the help of Mohamed, an Arab captain, they survive but they are quickly captured by the island's natives, the Amahagger people. They are to meet the Amahagger's white queen, whom they call "she who must be obeyed," whom the tribal people worship her as a god. Meanwhile, a woman kisses Leo and hugs him in public, meaning that they are married. In a fight to save Mohamed from their cannibalistic purposes, Horace accidentally shoots Mohamed and kills him, and Leo is wounded.
Together with Leo's new wife, they are taken to meet the queen, near Kor, an ancient city of runes. The queen lives below a volcano in a series of tunnels. The white queen is a witch named Ayesha, and she is so beautiful that all who see her without her veil are instantly in love with her and horrified by her. She is a witch and an alchemist. Ayesha agrees to heal Leo, but when she sees him, she is astonished, and she declares that it is Kallikrates, reincarnated. She heals him but banishes his faithful wife Ustane, but Ustane stands her ground. Ayesha kills her with magic. The witch then uses magic to make the men forget about the murder and they become fascinated by her again. Leo stays as her lover, Kallikrates.
The white witch takes Horace and Leo, along with Job, to the volcano. Leo is told to bathe in lava to cleanse himself of his mortality. He becomes reasonably concerned about the whole affair. Ayesha dips into the flames to prove that it is safe, but her second immersion brings an unexpected magical consequence—she reverts to her true age. As she withers and dies, she cries out not to let her memory die. Job is so stunned, he has a heart attack and dies.
