Brujo is an exploration of shamanism and curing among the Mazatec Indians of Oaxaca, Mexico, and among two groups of Maya Indians in southern Mexico and Guatemala. The film is divided into three sequences. The first, filmed in Chichicastenango (Guatemala), shows Diego, a shaman, cure a woman on whom a spell has been cast. The cure takes place partly in a church and partly in the mountains, where a sacrificed chicken is used to bring back the ailing woman's spirit.
The second sequence moves to Oaxaca, where a Mazatec shaman, her husband, and her patient consume hallucinogenic mushrooms. The cure, which takes place in darkness, involves a simple song (the mushroom's "voice") and dance, flowers, and the rubbing of tobacco on both the patient and the shaman's husband.
The final sequence takes place in the Chiapas highlands of Mexico, site of the festival and film Tajimoltik. The filmmakers encounter shaman Miguel, who brings them to his family home in a mountain hamlet beyond Chenalho. There he undertakes to cure filmmaker Claudine Viallon of a migraine, using candles, eggs, and incense. Miguel also discusses conceptions of the soul, death, and transmigration.