The story unfolds in a family of rich landowners from the colonial era, which owns a sugar plantation on the edge of the jungle. While hunting in the forest one day, the father, Don Everardo, discovers a young black orphan by the river. He brings the child to his mansion and call him Gaspar. Friendly and intelligent, the boy quickly becomes a new member of the family. He plays with his son, Sebastian, and his two daughters, Emma and Lucilla, as if they were his own siblings. The family occasionally have lavish receptions, with fine dining. One of Don Everardo's favorite mushroom dishes is prepared with an old family recipe from Spain. The family discovers if the mushrooms are edible making a servant to eat a few first. If the servant collapses and dies, then the family does not serve mushrooms to the party.
The family has another flirtation with danger: They keep a black panther called Toy chained in the main courtyard. From time to time it is released and chases people.
Some years pass, and Gaspar grows into a handsome young man, and daughters become beautiful women. They go into the woods hiking and swimming in the river. But the play of children has become flirtations, especially among young Gaspar and Emma. Along the way, Gaspar reveals his knowledge of different species of mushrooms that grow in the forest.
The family unit falls apart when Emma and her mother, Elvira, compete for the attentions of Gaspar. Elvira's flirtations with Gaspar provoke the jealousy of Emma, who releases the panther Toy to get rid of her mother. There is also a hint of a strange incestuous relationship between Sebastian and Lucila, older siblings.
When Don Everardo discovers the affair of his daughter Emma with the black servant Gaspar, he decides to make him his new "man of the mushrooms". But no one has the knowledge of Gaspar on mushrooms, and a lavish party at the farm will become a circus when Emma and Gaspar take advantage of the mushrooms to get rid of the rest of their own family and escape together.