Antonio is an aging man living in the remote Amazonian village of El Idilio. After arriving as an unsuccessful settler and losing his wife, he spends years observing the survival skills and customs of the Shuar Indians. Now existing on the fringes of both white and indigenous societies, he seeks solace by reading sad love stories with happy endings. He wears his dentures only when eating or when he wishes to speak.

The illegitimate son of an Iberian immigrant, this traveling dentist detests the government and all formal authority figures. He visits El Idilio twice a year on a supply boat to provide dental care and dentures to the settlers. He shares a quiet camaraderie with Antonio, supplying the older man with romantic novels collected from a larger town.

Sent to El Idilio as punishment for embezzlement in a larger city, this obese and continuously sweating official functions as the town's petty tyrant. The locals derisively refer to him as "Slimy Toad" behind his back. He busies himself with raising taxes, hoarding a private beer supply, and physically abusing his native domestic partner.

The Shuar are an indigenous community living deep in the Amazon Rainforest. They maintain a balanced, harmonious existence with nature, possessing strict boundaries and a clear moral code. They demonstrate generosity by teaching struggling white settlers how to survive, though they maintain a careful distance from those who violate their cultural rules.

A female jungle cat driven by intense grief after an invading hunter kills her unweaned cubs and injures her mate. Having tasted human blood, she actively stalks the intrusive prospectors and settlers near El Idilio. She functions as the physical manifestation of the natural world striking back against human exploitation.

The Amazon Rainforest functions as a living entity, balancing profound beauty with extreme danger. It sustains those who respect its rules, like the Shuar, but punishes those who approach it with ignorance or greed. It provides the central conflict as modern colonizers attempt to extract its resources.

Dolores is Antonio's first love and wife, heavily burdened by the societal expectations of their mountain home. When the couple fails to conceive a child, the surrounding community shames her with harsh gossip, prompting the pair to flee to the Amazon. She represents Antonio's innocent past before the tragedy of the jungle changes him.

Although born into a different tribe, Nushiño is welcomed by the Shuar and becomes a fully integrated member of their society. He and Antonio form an exceptionally close bond, hunting together and exploring the Amazon as equals. He requires proper tribal rites to ensure peace in the afterlife.

Onecén is a mountain-born settler living in El Idilio. He acts as an occasional intermediary between the corrupt local government and the isolated Antonio, bringing news of the mayor's plots regarding land ownership.

Josefina is a Black woman living in a nearby larger settlement. She maintains a relationship with the traveling dentist and enjoys reading romantic novels, passing her finished books along to be transported to Antonio.

A gold prospector who replaces his rotten teeth with gold pieces. His death at the claws of the ocelot escalates the town's fear of the animal and prompts a disastrous hunting expedition.

A settler who operates a miserable, isolated store in the jungle selling liquor, tobacco, and his namesake medicine. He lives alone after his wife leaves him for a traveling photographer.

A reclusive emerald prospector who stops at Alkaseltzer Miranda's store for a meal. He becomes collateral damage in the ocelot's escalating attacks against the encroaching white settlers.