Aretha, Paulo Vignolo and Donizetti are three children who meet Ossélio, a tiny skeleton model who comes to life and decides to transform science classes into a pleasant learning experience. By magic, Ossélio reduces the children to the size of a microscope, and they set out to discover the geniuses who control the parts of the human body: the hearing system, the brain, the vision, the vocal cords, the lungs, the heart, the bones, the digestive system and, finally, the uterus.