"Illness Dance" takes place in the Sacred Valley of the Incas in the Peruvian highlands in 1978. The story begins with a 1533 account of a child sacrifice high on Ampato Volcano in the Andes that took place shortly after the Conquistadors sacked the Inca capital at Cuzco. Three hundred years later two young students arrive at the same location and accidently witness the execution of two men by members of the Shining Path. The students investigate a stone box where the victims were digging and recover a rolled textile containing amulets, charms, and a quipu (counting device made of rope used by the Incas). They join their professor (Shelly Kelly) in Lima to turn in their find and tour Lima museums before leaving to conduct fieldwork at the ancient Inca fortress of Ollantaytambo. During the tour they meet two treasure hunters posing as archaeologists who want to join the crew in hopes of finding the fabled Golden Chain of the Incas made of two tons of gold. The younger treasure hunter is kidnapped by the Shining Path in Lima and his father and uncle-venture capitalists in New York who bankrolled the treasure hunters-come to rescue him. The uncle carrying the ransom money is murdered in a church in Pisac; the treasure hunter's other partner is drawn and quartered by the Shining Path; and the remaining treasure hunter (von Dinnegar) is nabbed by the Path, but escapes. He is recaptured and trepanated by a cult who believe a huaca (spirit) resides inside his skull. Local villagers descended from the Incas begin roaming the countryside speaking in strange voices-a phenomenon known as the Illness Dance in the 1500s-brought on by fear of the Conquistadors (and in this case, the Shining Path). Shelly's professor-friend (Lynn Hurley) mysteriously disappears in Ollantaytambo. During the ensuing investigation Shelly discovers a full-sized underground replica of the Temple of the Sun in Cuzco hidden under the streets of Ollantaytambo. It is populated by a group of Chosen Women and the mummies of four long-dead Inca kings. They also find the other half of the Ampato Volcano quipu. By combining the two quipu segments they decipher encoded clues that lead them to the Golden Chain-and to Shelly's near demise.