"The Storyteller" is a story of Saúl Zuratas, nicknamed "Mascarito" for a large, purple birthmark that covers his face, a college student who while on vacations In Florence stumbles into an exhibit on an indigenous tribe in Peru, the Machiguengas, who live along the banks of the Urumba River in Amazon Rainforest. Saúl decides to leave his past identity behind and immerse himself in the life and customs of the tribe.
The novel develops into an argument between the Amazonian cultures and modern civilization as Saúl's motivation for joining the tribe is questioned. In the book's odd chapters, Saúl and another narrator (most likely Llosa himself) debate politics, university, and the tribe versus modern society. In the concluding chapter, the narrator creates a commentary for public television convincing himself that the Machiguenga tribe is better off because of the modern influences imposed on them, and Saúl has fully immersed himself into the tribe's culture leaving behind the Western world and is serving as a liaison across between the Amazon members. The last chapter brings the narrator back to the picture in Florence. The narrator realizes the person in the picture must be his friend, Saul, and wonders about his fate.