This story covers a lot of plot, so let's start with a quick recap: A man and his god-son open a package that the god-son's father left for him to open on his 25th birthday. The package launches them into a full blown adventure to tribal Africa. They are captured by the natives, and the son is married to a girl named Ustane, but he is wounded. They go to the goddess/witch woman who lives under a volcano, and she heals him, but is convinced that the son is actually an incarnation of her divine husband. That immortal woman accidentally dies.
On the human level, that story does two things: It challenges the reader's assumption about the world, and it demonstrates the human fascination with transcendental concepts like magic, immortality, and truly irresistible beauty.
But on the level that Ayesha is experiencing, the story is completely different. She has been waiting for her lover's return for eons, and she accidentally found him in Leo. That means that Vincey's story might have more truth in it than Horace suspected. But it also means that Leo might literally be this reincarnation. When she takes him to attain immortality, she accidentally dies. The story is radically different from her point of view. From her point of view, this is an epic tragedy of reincarnating gods trying to spend some time together while working on their personal issues. To the regular people, it is an absolute horror. The servant Job literally dies from the terror of it all.