Moquedas, or "Tonto the Brave," as he is known to his companions Mehitabel Lee and Ronnie Jones, with whom he shares many adventures while hiking with them in the canyons around their town of Highland Boy. When they come across a deep abandoned mineshaft, Ronnie drops a pebble in to determine its depth. Instead of a rock-against-rock echo or the sound of a splash, they hear a screeching, throbbing wail as though from a tormented witch. Thus begins the adventure of a lifetime for the three companions. They are determined to learn more about the legends which have caused the people of Highland Boy to be fearful of the thundershowers with brilliant flashes of lightening and building-shaking thunder, that come to town the same time each year. The elders, the town marshal and doctor, relate stories of the old days: of a romance between ill-fated lovers whose mishaps in days gone by have led to the mysteries that cause the haunting, screeching laughter and wails of despair that accompany the thunder and lightening. Determined to end the grief of the lovers and end the troubles that plague the town, they set out to learn all they can and rid the town of its nightmare. Finally, in the coroner's dark, rat-infested warehouse, the adventurers find the key that will help them solve the mystery of the haunted mine and bring peace to their beloved town. They vow to return the key, a message of love, to its rightful place, in the haunted mine.