Volume One begins with the author announcing her intention to tell the story of her life. She has been adventurous and not stayed at home like the majority of women of her generation. Unca's grandfather was massacred on his plantation in Virginia, and her father was captured by the Native Americans who had invaded the plantation. A young Native American princess named Unca becomes enamored of him. She puts him in favor with the tribe's leader and negotiates his release and freedom, but Unca's sister has by this time begun to have feelings for him herself, and wants to marry him. William gently tells her that he loves only Unca but the sister is vengeful and furious. She tries to poison him and almost succeeds in killing him, but Unca saves his life for a second time. They leave the village and live amongst the settlers, where they shortly welcome a daughter, Unca Eliza, the author of the poem.
Alluca, Unca's sister, sends two men to kill Unca, and they try to stab her to death. William is so grief-stricken that he takes his infant daughter back to England with him, where he will also look after his brother, who is sick. Unca Eliza is raised a Christian amongst a number of cousins. When her father returns to Virginia she stays in England to finish her education but when she turns eighteen years old she and her cousin John make the journey to join her father. John asks Unca to marry him but she turns him down because he cannot use a bow and arrow better than she can.
When her father dies, she is left alone, returning to England at the age of twenty four. The captain of the ship she is sailing on proposes, and is turned down, but is so angry that he leaves her marooned on an uninhabited island. She turns to God for help and is led to a small hermitage where she find a manuscript left behind by the island's previous inhabitant, that is a blueprint to surviving the island. She explores the island, finding an ancient temple and learns that there are Native Americans on the island. She vows to convert them to Christianity. However, only the priests return to her for instruction because their job is to convey her teaching to their subjects. Unca decides to live amongst the Indians because she doesn't trust the priests to instruct them properly.
She tells the Indians that it is written that a high priestess will come to them, and that they must listen to her. She dresses like such a woman and they accept her, sharing their food and drink, and listening to her preachings.Much of the time, she sings or speaks in the Indian's own language, so that they are able to liken the Christian rituals she is teaching them to their own. She also translates the Bible and her prayer book for them. She isn't happy living among them but is happy that she has brought Christianity to the island.
When she sees Europeans approaching she fears for the future of the Indians and wants to protect them from European enslavement. Shocked, she recognizes her cousin amongst the men on board the ship that is heading towards the island. She calls to assure him she is alive, and also asks him to sing a hymn that was written by her uncle. Her cousin is relieved to see her alive but the ship's company are terrified of her Oracle and of the way in which she appeared to them. Her cousin tells her that after the ship's captain abandoned her on the island, he was captured by Captain Shore, who returned to look for her. However the crew are now so scared of her that he fears they will not let her on board the ship at all.
The men are so convinced that Unca is the spawn of Satan that they have also banned her cousin from the ship. He sits with her whilst Captain Shore attempts to reassure them that they have not, as they continue to claim, seen her rising from a pyre of fire and brimstone. Shore accuses the sailors of mutiny . Meanwhile, Unca introduces her cousin to the Indians who have never seen a white man before. Her cousin wants to join her on the island and work as a missionary, and although she is not enthusiastic about this, they are left with no choice when they learn that Captain Shore has started the journey back to England and vowed to return with a different crew in a year's time. Cousin Winkfield is quite delighted because it means he can try to persuade Unca to marry him. She begins to consider his offer so that they can be together in the eyes of God.
The Winkfields introduce more livestock to the island, as well as a gun and a telescope which makes the Indians like Unca's cousin immediately. Unca marries him within two months because of his ability to preach and the fact that he has learned the Indian dialect in a mere two months.
A year later, Captain Shore returns as planned. He informs Unca that the captain who abandoned her on the island was hung for treachery. Shore pardoned his previous crew who had refused to let Unca board the ship. Shore, who has found God and repented his wrong doings, wants to remain on the island, which Unca agrees to. Winkfield and Shore return to England to obtain their families' permissions for them to leave Europe forever, and when it is granted, all three vow never to go back to Europe again.
